The brief, filed in the federal District Court for the Northern District of California, urges the Court to block Trump administration immigration policies, which the prosecutors and law enforcement leaders believe undermine the trust between local police and immigrants in their respective jurisdiction.

It also supports the State of California’s lawsuit against the Justice Department. The California attorney general, Xavier Becerra, initiated the lawsuit after the Justice Department threatened to cut off funding for sanctuary cities if the cities refused to cooperate with immigration agents and policies. 

Through the lawsuit, California intends to block the Justice Department from placing new immigration conditions on federal grant money for local law enforcement from the Edward Byrne Memorial Justice Assistance Grant and Community Oriented Policing Services programs. 

New conditions for receiving the grants would require local jurisdictions to desert prior policies which helped law enforcement foster more trusting and cooperative relationships with immigrants. 

Prior policies prohibit local law enforcement from inquiring about immigration status and protect the confidentiality of victims and witnesses. 

Siemon and fellow signatories of the brief said trust from the community results in quality local police work, public safety, and successful prosecution. The brief argues with new Trump administration policies, undocumented immigrants and families would abandon trust and cooperation with local authorities. 

“The criminal justice system functions best when we work with all members of our community in a process predicated on cooperation and trust,” Denver District Attorney Beth McCann said in the release. “All of us will lose if federal funding for important local law enforcement initiatives is tied to conditions that would require jurisdictions to prioritize civil immigration enforcement over promoting public safety and protecting the confidentiality of victims and witnesses.”

Prosecutors and law enforcement leaders who signed on to the brief fear new policies create distrust among immigrants.

“We have already seen evidence over the past few months of a reluctance by immigrant communities to report crimes and cooperate with law enforcement and prosecutors based on a fear of deportation,” former federal prosecutor Miriam Krinsky said in the release.