An emerging research literature establishes that police unions, and the police union contracts and laws they’ve worked to enact, are associated with a range of problematic policing outcomes. A review of the available research literature on police unions by the Journal of Police Practice and Research found “virtually all of the published items that express an opinion on the impact of police unions regard them as having a negative effect, particularly on innovation, accountability, and police — community relations.” In one of the first studies examining this issue, Professor Samuel Walker and Kevin Keenan documented in 2005 how police unions helped to enact statewide police bill of rights laws with provisions that constitute “impediments to police accountability” such as the establishment of formal waiting periods that delay investigations; prohibitions on the use of [civilian] investigators in misconduct investigations; statutes of limitations on the retention and use of data on officer misconduct; the failure to allow for reasonable exceptions to provisions regulating the time, place, and manner of investigative interviews; excessive limitations on how many officers can participate, how many can speak at one time, and the use of “foul” language; and requiring the disclosure of the names of complainant(s) in every case, among other issues. 

Subsequent research has examined the ways in which police union contracts, in addition to these state laws, contain similar problematic provisions protecting officers accused of misconduct. For example, an analysis of Baltimore’s Police Union Contract found the contract contained provisions that worked in concert with the state police bill of rights law to “impede the effective investigation of alleged officer misconduct and shield officers from discipline.” In addition to their impact on police accountability, researchers have also found that some of these provisions - most notably provisions delaying interrogations of officers - are based on faulty science. In 2015, Campaign Zero worked with researchers and legal experts to review and publish for the first time the police union contracts for 81 of the 100 largest US cities as well as police bill of rights laws in 15 states - finding six ways in which these contracts and laws could make it more difficult to hold officers accountable for misconduct. In 2016, University of Chicago's Aziz Huq and Richard McAdam’s argue that “Delay Privileges” and “Interrogation Buffers” found in bargaining agreements, state laws, and municipal codes provide officers with heightened procedural protections which have the “predictable effect to obstruct investigations.”   Building off of the Campaign Zero framework, Professor Stephen Rushin published a review of 178 police union contracts in the Duke Law Review in 2017, finding “a substantial number of these agreements limit officer interrogations after alleged misconduct, mandate the destruction of disciplinary records, ban civilian oversight, prevent anonymous civilian complaints, indemnify officers in the event of civil suits, and limit the length of internal investigations.” Reuters conducted a similar analysis of police union contracts in 82 cities, finding “cities have bargained away the power to discipline police officers, often in closed negotiation meetings with local unions” and identifying broad categories of contract protections for officers such as provisions that disqualify complaints of misconduct, erase disciplinary records, give officers preferential access to evidence, and allow officers to substitute vacation or discretionary time for suspension. Finally, a study published in the University of Pennsylvania Law Review examined police union contracts in over 600 cities and found that, under the disciplinary appeals processes established by these contracts, “police departments must often rehire or significantly reduce disciplinary sanctions against officers who have engaged in serious misconduct.” 

Researchers have also begun to examine the relationship between the problematic provisions in police union contracts and police bill of rights laws and a range of negative policing outcomes. For example, a Washington Post analysis of 1,881 officers fired by the nation’s largest police departments from 2006-2017 found that “departments have been forced to reinstate more than 450 officers after appeals required by police union contracts.” A 2018 study by Professors Dharmapala, McAdams and Rappaport found evidence that “collective bargaining rights led to a substantial increase in violent incidents of misconduct among sheriff’s offices...the effect of collective bargaining rights is concentrated among sheriff’s offices that subsequently adopted collective bargaining agreements, and the timing of the adoption of these agreements is associated with increases in violent misconduct.” A 2018 study from Oxford researcher Abdul Rad found that places with the types of problematic clauses in their police union contracts and police bill of rights laws that Campaign Zero identified were also associated with higher rates of police abuse, though it cautions that it’s difficult to prove the relationship is causal. Finally, in a forthcoming study from economists at the University of Victoria, researchers found that after officers gained access to collective bargaining rights that there was a substantial increase in killings of civilians - comprising an estimated 60 to 70 additional people killed by police per year, the overwhelming majority of whom were people of color.

Researchers have also begun to document the ways in which police unions have influenced legislators to enact these laws and contracts - and to block police accountability legislation. A Campaign Zero analysis of police union lobbying and political contributions in California found that police unions had contributed to 118 of California’s 120 state legislators from 2011-2017 and spent over $2 million in lobbying the state legislature during a one-year period - substantially more than had been spent by racial justice organizations within the state or even the NRA. A nationwide analysis conducted by NoMoreCopMoney, using data obtained from the National Institute on Money in State Politics, found that the political action committees of police unions and associations had donated over $19,600,000 to 3,530 state and local politicians since 2015. Both analyses found that police union contributions disproportionately went to Democratic politicians, with Campaign Zero’s analysis also finding that police unions contributed most to Democrats who opposed police accountability legislation. Another study found how police unions work to block “sunshine laws” that would make records of police misconduct available to the public. Professors Catherine Fisk and L Song Richardson identify a number of additional ways in which police unions block systemic changes to policing from being implemented, including how police unions utilize state laws to force cities to negotiate over changes to police disciplinary processes, use of force reporting and investigation procedures, the size and scope of the police force, and other changes deemed related to “conditions of employment.” For example, a review of 17 cities where the US Department of Justice mandated police reforms found at least 7 cities (41%) had reforms blocked due to their police union contracts.. 

Altogether, the existing body of research shows how police unions wield considerable influence over the politics and policy concerning police accountability - and that they have used this influence to put in place a special set of legal and administrative protections that are associated with higher rates of police misconduct and lower rates of police accountability. The NixThe6 campaign builds from this foundational research and translates it into a call to action for communities and lawmakers to dismantle these barriers to holding police accountable and, in doing so, make communities safer.