Mini Review Volume 11 Issue 3
Administration of Justice, Texas Southern University, USA
Correspondence: Gloria Okere, Administration of Justice, Texas Southern University, USA
Received: August 16, 2023 | Published: August 28, 2023
Citation: Okere G, Bush LSN. Qualified immunity: unveiling police violence and misconduct in the United States. Forensic Res Criminol Int J. 2023;11(3):105-110. DOI: 10.15406/frcij.2023.11.00376
Police violence and misconduct have been evident throughout American history. The earliest forms of policing began in the 1700s in the Carolinas with “Slave Patrols”. It was established to terrorize and suppress enslaved Africans and to apprehend and return the runaway slaves to their owners.1 During the 1960s, direct causations of racial tension and riots was also a conjunction with President Lyndon Johnson’s “War on Crime” initiative. This section documents the history of police violence and misconduct between the periods of 1960 through the early 2000s. The overlapping theme of qualified immunity highlights a prominent role in issues arising from civil rights and accountability.
Keywords: prohibited conduct, the duty to intervene, police violence, police misconduct, qualified immunity, fruit of the poisonous tree doctrine, cariol’s law, accountability, law enforcement reform, civil rights, justice, excessive force, thin blue line, blue wall
The origin of policing is one that can be traced back to the days of slavery and has evolved as a means of protecting ordinary cities and maintaining order. The function of policing includes a variety of agencies where current police strategies have come into question that surrounds the theme of racial profiling and corruption. Policing in Colonial America from the early 17th century until the formation of the Thirteen Colonies in the United States until after the Revolutionary War, has been funded by a privately funded system and considered as a local responsibility that focuses on maintaining both internal and external order. The following paragraphs will address the history of policing in America which highlights a timeline of officer-involved shootings, media outrage, and social and political issues that later considers police reform.
Issues in policing
In the United States, the desire to maintain order is a component of the criminal justice system which has origins rooted in slavery. The police,” as a civil force charged with deterring crime, came to the United States from England and is generally associated with monarchy— “keeping the king’s peace”—which makes it surprising that, in the antimonarchical United States, it got so big, so fast. The reason is, mainly, slavery.2 Known as modern day policing, slave patrols were utilized that consisted of organized groups of armed, white men. These men monitored and enforced rules planted upon slaves and their daily activities as a means of enforcing state laws. The institution of slavery and state laws were designed to control and shape the behaviors of minorities. For example, considering how slavery itself was one of the most egregious treatments of mankind in human history, slave patrols were especially cruel in the ways they captured runaway slaves and punished them for their daring escapes.3 The first slave patrols came about in South Carolina during the early 1700s. Tactics of captivity included the use of excessive force of a group of about ten males, organized together, whose primary focus was on the idea of maintaining social order as it pertained to race. Without any warrant or permission, slave patrols would enter the home of residents instilling fear and terror as a means of deterring slaves from running away, while disciplining and returning those captured. Maintaining law and social order were phrases used to win political campaigns such as President Nixon’s 1968 political campaign that centered on controlling environments deemed with hostility, anger, and violence. After the Civil War ended, slave patrols dissolved and were revamped in that of Black and Jim Crow laws. Black codes restricted the freedom of African Americans and was based on the premise that slaves were property, and they had few or no legal rights. In the late 1880s new forms of Black Codes known as Jim Crow laws were enacted across southern states. Police corruption and violence arose through state laws such as Jim Crow emerging in the late 1900s and early 20th century. Jim Crow laws specifically enforced racist government policies against African American individuals. It was based on the premise of white supremacy, which restricted voter rights, legalized segregation, and denied educational and housing opportunities for African Americans.
The interest of social control became greater than crime control. During the 1960s, the Civil Rights movement brought about 100s of individuals who came together to challenge police brutality and the use of deadly force. The Civil Rights Movement was a movement for African Americans to combat racial control, white supremacy, and police brutality. The Civil Rights Movement of the 1950’s and 1960’s came about out of the need and desire for equality and freedom for African Americans and other people of color. Nearly one hundred years after slavery was abolished, there was widespread segregation, discrimination, disenfranchisement, and racially motivated violence that permeated all personal and structural aspects of life for black people.4 During this timeline, many riots broke out in urban communities during a heightened outpour of activism. These include repeated violent oppression of African Americans such as the riots that destroyed Black business owners’ wealth on the Black Wall Street in Tulsa, Oklahoma in 1921, codified segregation, legal racial terrorism during the almost century long period from Reconstruction to the civil rights era, systematic exclusions of African Americans from better-paying jobs and continued occupational segregation.5
The civil rights movement challenged police brutality that arose and other forms of racial segregation. Police brutality is defined as the use of excessive physical assault or verbal assault during police procedures, such as apprehending or interrogating a suspect. Deadly force is not always excessive force. However, when deadly force exceeds the force that is necessary to create a safe environment, it is considered police brutality.6 Forms of police brutality range from unlawful arrest or detainment, excessive force, racial abuse, verbal and physical attacks, and malicious prosecution to name a few. This contrasts with what a police officer stands for. A police officer is a government employee who protects lives and property through laws and regulations. A police officer is a representative and enforcer of law and order whose job it is to serve and protect the citizens. Police officers respond to emergency calls, make arrests, patrol neighborhoods and roads, and ensure the safety of the community. Each police officer is assigned to a jurisdiction where they work.7 Police officer and law enforcement officer are sometimes used interchangeably. There are more than 17,000 state and local law enforcement agencies in the United States, ranging in size from one officer to more than 30,000. Local police include municipal, county, tribal, and regional police that derive authority from the local governing body that created it. The primary purpose is to uphold the laws of the jurisdiction, provide patrols, and investigate local crimes. State Police/ Highway Patrol State police often perform police duties to include highway patrol and statewide investigations. Some states have only highway patrol with investigative functions covered by a separate entity such as a state bureau of investigation.8 On the federal level, federal police are charged with tasks such as protecting the United States against terrorist threats, border protection, railway policing and aviation security. Federal police also have similar jobs as local and state police officers. Police officers provide a wide array of services that at times are outside the scope of crime. Types of police officers’ range in terms of rank such as a Chief of Police who is the highest rank in a police department to game wardens who are referred to as wildlife officers commissioned to protect wildlife and natural resources.
Police conduct
Police officers in the United States take on many roles and duties. Besides protecting life and the property of others, police officers conduct hearings, investigations, settle disputes, arrest suspects, and respond to emergency and non-emergency situations. Police officers have a code of conduct that they are required to adhere to. The police code of conduct works in conjunction with the law enforcement code of ethics. The code of conduct consists of ethical mandates law enforcement officers use to perform their duties. These guidelines include acting impartially; exercising discretion; using only necessary force; and maintaining confidentiality, integrity, and a professional image always.9 The political era of policing occurred in large cities such as Boston around 1828, in New York city around 1844 and Philadelphia around 1854. Policing during this time centered on politics accompanied by the Industrial Revolution. During this era, police represented the local politicians in the neighborhoods that they patrolled. There was no civil service system, so the police were hired, fired and managed at the discretion of the local politicians. Politicians ran precincts as small departments.10 Police officers swayed away from this type of policing during the Reform Era of policing known as the Progressive Era. From 1890 to 1920 the reformers of the Progressive Era tried to carry out social, economic, and political changes in the cities, including changes in police departments. A second reform movement emerged in the failure of the Progressives, with efforts to professionalize the police with the assistance of leadership and technology.11 Politics that influenced policing became unfavorable in an effort to reform police departments on a national level. The progressive era was also influenced by the influx of migration within the United States and urbanization.
During this era, eliminating corruption from the government was vital towards police reform and initiating police officers as social workers. The first police officers as social workers were women, although there was a strong opposition in hiring females as police officers in the late 1890s. Policewomen, as they were called, were tasked with overseeing juveniles, caring for and searching women inmates, and completing desk work of criminals. In the early 1900s, policewoman moved into the roles of patrol, as well as investigating crime and delinquent behavior. Mrs. Wells was named the first president of the Women’s Peace Officers Association of California in 1928, a group she helped to create. In July 1934, she was appointed the Los Angeles Police Department historian, a post she held until her retirement on November 1, 1940. She had been a policewoman for 30 years. Since her appointment, policewomen have been assigned duties in patrol, delinquency prevention, investigation of crimes involving juveniles, and investigation of other cases in which the service of a female officer is deemed necessary.12
Police officers taking on the role as social workers enhanced skills that reinforced procedures pertaining to law enforcement, and the rights of individuals. Today, police social work represents a small specialty area within police departments. During the early 1800s, the founder of modern policing, Sir Robert Peel, regarded police officers as “the public,” he said, “and the public are the police.” Peel is credited with nine principles including one stating that police should use “only the minimum degree of physical force” to do their jobs, which is to keep the peace and enforce laws.13 The nine principles that he penned nearly 200 years ago are just as important to proper police operations today as they were in early nineteenth-century London.
Nine pillars
Police conduct is parallel to its relationship with the citizens within the community in which they serve. Police officers depend on the citizens through its partnerships in order to conduct investigations and solve crimes. Whereas citizens depend on police officers to protect them and maintain social order by implementing laws and rules that are in place. The relationship between police officers and citizens centers on community policing. Community policing is a partnership between law enforcement and its residents. Community policing is defined as involving three key components: developing community partnerships, engaging in problem solving, and implementing community policing organizational features. Community policing encourages interactive partnerships between law enforcement agencies, their officers, and the people they serve. By developing connections within the community, police are better informed and empowered to solve public safety problems.15 By establishing a collaboration with the residents, police officer are better equipped to solve problems that arise and use strategies that build trust and improved community relations.
Police misconduct
Police misconduct is described as any inappropriate conduct or behavior that may be illegal or a department policy violation in connection with the official duties that can intimidate, coerce, brutalize, or mislead others into a false outcome in a criminal or civil case against a civilian. Some common police misconduct actions are:
Race relations between the police and minorities in the United States have been a continued problem since the slave patrols in the early 1700s. In the wake of the death of George Floyd, 46-year-old unarmed black man, after a convenience store employee called 911, telling the police that Floyd bought cigarettes with a counterfeit $20 bill. Minneapolis, Minnesota police officer Derek Chauvin suffocated him after placing his knee on the neck for several minutes, again igniting race related protest not only around the country but around the world. Four officers, including Chauvin, were convicted of several offenses in the case including excessive force. The department itself was investigated this department for civil rights violations. The Department of Justice investigated more than twenty police agencies concerning misconduct violations against African Americans and found that police departments have a pattern of civil rights violations including excessive force which disproportionately affected Black and Native Americans. The police agencies including the Minneapolis Police Department entered into approved agreements to try to correct the problems, but after the change from Obama to Trump administration, the investigation was halted, citing it would demoralize the police agencies. Shaun Gabbidon in Criminological Theories on Race and Crime (2010) theories that the idea of “Negophobia” the irrationality of Black which includes a fear of being victimized by Blacks can result in the decision of Whites shooting or harming African Americans based on racial bias or stereotypes.
Law Enforcement Officers in the United States have a very difficult job to perform but are expected to conduct themselves according to a higher standard than that set by ordinary citizens. No officer is above the law and when this sworn duty is violated this is considered police misconduct. United States Department of Justice Civil Rights Division investigates Law Enforcement misconduct. The Department investigates allegations of alleged Constitutional violations and obstruction of justice which includes officers attempting to prevent or obstruct witnesses or victims from reporting such incidents. Whether the DOJ brings forth criminal charges against the accused officer or civil charges against the law enforcement agency, the Department must be able to establish that it is probable that a crime was committed, and they have a changed and proving the allegation are true. In criminal cases must establish “proof beyond a reasonable doubt” and civil cases only need proof of “preponderance of the evidence”.
Police Departments in the United States differ in size, training, and education of these organizations can influence police misconduct. Police Misconduct is not new, in the early 1800-1900 law enforcement officers began to expand because cities and counties began to grow because of the influx of immigrants into the county. As police departments began to expand so did their duties and responsibilities. As different cultures and languages began to emerge, different forms of discrimination also began to emerge. The civil disorder became increasingly worse, especially in the South, where slavery flourished and the government began creating laws that directly affected the enslaved Africans and newly immigrated migrants into the United States, such as curfew laws and vagrancy laws. To enforce those laws, police brutality and the use of excessive force were commonplace and used to elicit confessions and instill fear in those who dare to break the law.
Professor Tom Tyler of Yale Law School in his seminal study of Chicago, conceived legitimacy as not only “support for legal authorities” but also a “perceived obligation to obey,” and the latter aspect—obligation—is prominently featured: “When people feel that an authority is legitimate, they authorize that authority to determine what their behavior will be within a given set of situations.” 16 Although in this chapter we will not go into an in-depth discussion about how the factors of race that influence the perceptions, Whites, African Americans, and Hispanics view and are victims of police misconduct differently. Whites tend to have a more favorable opinion of the police than those of African American descent. African Americans and Hispanics tend to view police as more of an antagonist than a protector. Although findings associated with race and ethnicity of officer misconduct have mixed reviews, race remains a key factor in structuring attitudes toward police. Explanations of police misconduct are generally divided into two theories: “bad apples” and “bad institutions.” At the individual level, bad-apple theories stress that police misconduct is related to officer-level factors, such as age, race, gender, education, temperament, and experience.17 In addition to the question of whether someone has experienced any form of police misconduct, it is important to remember people are somewhat less likely to report abuse or regard police abuse as commonplace.
Police culture
The culture of police is exhibited through a shared set of attitudes, beliefs, values, and behaviors that officers illustrate daily. Police culture centers on the organization and structure of police work; including laws and restrictions imposed. The premise of police culture centers on ‘maintaining order’ and the flow of disseminating information from top to bottom in their organization. This includes management of police organizations relating to personnel and activities. Successful management of culture is achieved in three ways:
Leadership through values allows those in leadership to lead through a sense of purpose which includes responsibilities and an integration of the people within their community. This relates to accountability to the community with police officers holding one another accountable for their actions. Police officers are then able to work collaboratively and fairly to empower communities that maintain trust and faith in the system. Administrative mechanisms of control relate to internal forces that are the drivers within the police organization. Police oversight focuses on the internal and external mechanisms that police departments use to ensure that officers follow both governing legal rules and their own agency’s administrative policies and training. Unlike internal oversight, external oversight goes outside of the traditional command and control mechanisms that have evolved within police agencies by involving agency outsiders in the form of civilian review boards, consent decrees, or individual litigation.18
Ethics and accountability
In the early 1930's President Hebert Hoover convened an 11-person panel charged with addressing the continued problems of alcohol prohibition and organized gang activities. The Wickersham Report was of its kind to investigate federal investigation into law enforcement practices. Attorney General George W. Wickersham chaired the 11-person panel and found during the investigation, widespread corruption, officers used excessive force, made threats of harm, and physically abused those they interrogated and interviewed. The goal of law enforcement in any hierarchy is to hire those with the highest caliber of moral and ethical behavior. This behavior must be exhibited while an officer is both on and off duty. The International Association of Chiefs of Police (IACP) oath is, “On my honor, I will never betray my badge, my integrity, my character, or the public trust. I will always have the courage to hold myself and others accountable for our actions. I will always uphold the constitution, my community, and the agency I serve.”19 Ethics can be defined as the ability to know right from wrong and uphold our obligations even when there's no one watching. Good officers with character will always respect themselves and will not make unethical decisions that could jeopardize the health, safety, and well-being of themselves and those around them.
Later, Congress established the US Department of Justice Civil Rights division in 1957 to address the peaceable and constitutional rights of all Americans particularly those who have their rights violated by police misconduct by law enforcement agencies. Whether the agency is large or small, officers are sworn to protect and serve, it's not only a decal on a patrol vehicle it is also a code to live by. Officers are sworn to uphold these codes of ethics on the first day on the job and must respect the constitutional rights of liberty, equality, and justice for all no matter their gender, race, creed, or color. The American Psychological Association includes six principles within its guidelines for the ethical decision-making process, they are competence, integrity, professional and scientific responsibility, respect for people’s rights and dignity, concern for others’ welfare, and social responsibility.20 There are two categories of unethical behavior described in law enforcement "meat eaters" and "grass eaters". Grass eaters can be described as officers that are willing to accept a free cup of coffee or a meal at their favorite establishment or a discounted rate.
The business in a sense understands that if they have several police officers at their place of business it may deter crime. These gratuities may or may not be accepted within the department's policy to fend off corruption. Corruption sometimes may be a small ethical decision to make, or this could lead to a much larger willingness to engage in illegal behavior or corruption within the department. Sometimes this can be seen as a test of loyalty to the department by senior officers to new incoming officers or it's a test of strength in the code of silence within the police culture that's being considered the blue wall of silence. Meat eaters can be described as those officers that exhibit unethical behavior that is willing to take a bribe or a substantial amount of money for a favor or engage themselves in criminal activity. Both behaviors are found to be problematic, however, some police agencies within their policy may allow the grass eater to accept small, valued items such as a cup of coffee or if that item is donated to the entire department or group instead of just one individual or person. Law enforcement agencies have lately been dealing with unethical behavior by law enforcement and are continuing to address concerns of those who tend to violate this code of ethics and conduct.
5 of the most notable Police Misconduct Cases in the 20th and 21st century in the United States
John Spencer – Fabricating Evidence (1993)
A New York Stated police lieutenant admitted to fabricating evidence in several cases including in the case of John Spencer. The officers would fabricate evidence to build a stronger case against the individuals already in custody. They wanted to strengthen the evidence against Spencer to support a homicide charge in which he was sentenced to 50 years to life in prison, but he asked the judge to vacate his decision because evidence in the case was faked. He was not released, the fingerprints planted had no bearing on the outcome of the double homicide case in which he was convicted.
Rodney King – Police Brutality (1991)
In Los Angeles, California, officers in the Los Angeles police department attempted to pull over Rodney King on a traffic offense of speeding; Mr. King led the police on an 8-mile police chase. When Mr. King pulled over, he was beaten and tased repeatedly by police. At that time, it was the worst case of police brutality caught on video. Mr. King won his civil lawsuit against the police officers.
George Floyd – Police Brutality (2020)
In Minneapolis Minnesota, George Floyd was killed while in custody of police after the police was called to the scene for possible use of a counterfeit bill being used at a convenience store. The brutal treatment of Floyd by police officers was also caught on video. One of the officers kneeled on Mr. Floyds neck while he was handcuffed, violating numerous department policies, killing him. This event touched off world-wide protest in part due to the COVID-19 pandemic, most of the world was at home watching the events unfold life on television. The officers were fired after Floyd’s death and charged and convicted with several crimes, including second-degree murder, and aiding and abetting second-degree murder.
Philando Castile – Excessive Force (2018)
In Minneapolis Minnesota police pulled over motorist, Philando Castile for a traffic stop citing he had a broken taillight and resembled a robbery suspect. Mr. Castile, a licensed gun owner, informed the officer he had a legal firearm in the vehicle. He agreed not to reach for the firearm. After complying with the officer’s request for his identification, the officer fired seven times into the vehicle when Castile reached for his identification. The officer killed Castile in front of his child and girlfriend, who were in the vehicle with Castile. Mr. Castiles’s girlfriend was able to live stream the aftermath of the killing on social media.
Tyre Nichols- Excessive Force (2023)
In Memphis, Tennessee, Tyre Nichols died three days after being beaten and pepper-sprayed by police during a traffic stop by five Memphis police officers. A combination of body cam and surveillance camera video released by the city showed the beating that Nichols endured in detail. The officers were accused of using excessive force and either obstructing or turning off their Body Worn Cameras.
Qualified immunity
Community activists, scholars and public leaders are calling to end or limit qualified immunity, citing it undermines accountability and purpose and it shields government from prosecution. Some proponents of abolishing qualified immunity say not only does qualified immunity exceed its constitutional authority, but it has a significant financial consequence to the city and not the violator itself. Law enforcement and government agencies describe qualified immunity as a critically important factor in government without fear of reprisal when acting in “good faith”. Law enforcement sometime must make split second decisions in a life and death situation and any hesitation may be catastrophic. Qualified Immunity is a legal principal that is used to protect law enforcement officers and other government officials from civil prosecution if an action is taken while holding office unless the citizen can clearly establish that the official violated their constitutional rights. Qualified Immunity was enacted to protect those who were said to be acting in good faith if acting in their official capacity or within the “color of the law”.
In 1871 Congress adopted the 42 U.S.C § 1983, which makes government employees and officials personally liable for money damages if they violate a person’s federal constitutional rights. Which defines qualified immunity as the doctrine of qualified immunity protects state and local officials, including law enforcement officers, from individual liability unless the official violated a clearly established constitutional right. For suits against federal officials, the structural account articulates a poor compensating adjustment because qualified immunity supplies an awkward solution to any separation-of-powers problem. For suits against state officials, the structural account appears to rest on a notion of “freestanding federalism” that is too far removed from the actual constitutional design. Contrary to the common-law tradition granting absolute immunity to prosecutors, there is no comparable protection granted to police officers who file complaints that causes the issuance of a warrant. Since the statute on its face does not provide for any immunity from §1983 liability, the Court “would be going too far to read into it an absolute immunity for conduct which was only accorded qualified immunity in 1871.”21,22
Pros and cons of qualified immunity
The benefit of qualified immunity greatly meets the needs of officers and other government officials by offering some sort of protection against prosecution if in the furtherance of their duties they acted in “good faith”. Police officers sometimes must make slit second decisions that may be life or death situation and hesitation could lead to harm of the public. Removing qualified immunity could open officials to meritless lawsuits what may lead the courts to second guess the action of the officers in the slit second decision. Qualified immunity and absolute immunity are distinctly different, officers have been held liable if constitutional rights are violated. Qualified immunity is essential to effective policing in that it shields officers from financial ruins. The argument qualified immunity reflects the public perception that law enforcement officials are above the law and aren’t held accountable for their actions. In the case of law enforcement, the “blue wall” allow officers to protect themselves over the well-being of the public. Necessary liability needs to be in place to protect citizens and hold law enforcement and government officials accountable. Police agencies themselves are held accountable monetarily if a constitutional violation is found and liability is not found with the individual officer, so the fear of meritless lawsuits is false. Absolute Immunity should be available to whistleblowers.
The George Floyd justice in policing act of 2020
This bill addresses a wide range of policies and issues regarding policing practices and law enforcement accountability. It increases accountability for law enforcement misconduct, restricts the use of certain policing practices, enhances transparency and data collection, and establishes best practices and training requirements.
The bill enhances existing enforcement mechanisms to remedy violations by law enforcement. Among other things, it does the following: lowers the criminal intent standard—from willful to knowing or reckless—to convict a law enforcement officer for misconduct in a federal prosecution, limits qualified immunity as a defense to liability in a private civil action against a law enforcement officer and grants administrative subpoena power to the Department of Justice (DOJ) in pattern-or-practice investigations. It establishes a framework to prevent and remedy racial profiling by law enforcement at the federal, state, and local levels. It also limits the unnecessary use of force and restricts the use of no-knock warrants, chokeholds, and carotid holds. (H.R. 7120, Congress 2020)
Cariol’s law- duty to intervene
Cariol Horne, a former Buffalo police officer was fired in 2008 after intervening when a fellow officer used excessive force while placing a man in a chokehold. Ms. Horne stated she grabbed her partners hand from the man’s neck to prevent her partner from harming the man. Ms. Horned stated in her attempt to intervene she was assaulted herself and retaliated against by the department. After her termination, Ms. Horne was denied her pension from the department until 2021, she later introduced Cariol’s Law, which provides protection to officers who intervene when officers are using excessive force.
Duty to intervene
Duty to intervene or DTI are measures established that require officers to intervene in situations where exceptional circumstances are probable. Some police agencies have adopted policies that require officers to intervene in situations where officers exceed their agencies’ directions on use of force. Such agencies may also prohibit the use of chokeholds which is like neck restraints that may cause significant harm or even death unless the officer reasonably believes the life of the officer or victim is in danger.
Policing ahead
Police systems differ in organizations due to theories of policing that exist. Theoretical theories such as ‘broken windows’ indicate that visible signs of criminal activity exist that purport towards civil disorder and misbehavior. General theories explain traditional forms of crime along with police misconduct and crime control. Police strategies involve proactive planning and resources to include innovative approaches towards community safety. Police officers at times are the first responders to issues that surround criminal activity, mental issues, substance abuse and poverty. With the advancement of technology in a complex world, police officers are faced with new opportunities as well as challenges regarding security. Real time crime centers are useful in this sense which provides monitoring of criminal activity in real-time through surveillance cameras. Police can use a similar data analysis to help make their work more efficient. Surveillance cameras are efficient in not only crime reduction, but also providing valid evidence of criminal activity occurring. Identifying potential criminal activity uses data analysis from disparate sources in order to predict and respond effectively. The idea is being called “predictive policing,” and some in the field believe it has the potential to transform law enforcement by enabling police to anticipate and prevent crime instead of simply responding to it.23–27
None.
The author declares there is no conflict of interest.
©2023 Okere, et al. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.