It appears that, in violation of California law, police are using disappearing message apps so that there will be no proper record of their misdeeds:

In a disturbing trend, government officials and police departments have been thwarting public oversight by using communications apps that automatically delete messages.

The latest example comes from Southern California, where an investigation by Al Jazeera and the ACLU of Southern California revealed last week that the Long Beach Police Department was using an app called TigerText to send self-erasing messages. The department’s effort to subvert transparency appears to have been intentional: Supervisors were instructing officers to use the app whenever they wanted to keep potentially damaging information secret — including in cases of police killings.

The LBPD’s decision to systematically destroy communications is an outrageous violation of California’s public records laws and the legal obligation to preserve records that could come up both in criminal cases and civil rights lawsuits against the department. And this decision — made by the police department in the city ranked the 13th deadliest in the nation for police killing — is also a glaring example of the mindset of impunity that prevails in some police departments.

We really need a Federal law enforcement agency which is single tasked with policing the police.