CHICAGO — Chicago officials are pledging to revamp the city Police Department following a scathing federal report, but a change in presidential administrations could spell uncertainty for the critical next step in the process: negotiating a court-enforceable improvement plan with the Justice Department.

A report released Friday in the final days of Attorney General Loretta Lynch’s tenure found that police in the nation’s second-largest department had violated the constitutional rights of residents for years, including the frequent use of excessive force, shooting at people who did not pose imminent threats and using stun guns on others only because they refused to follow commands.

The report was the culmination of a yearlong investigation, one of about two dozen civil rights probes of local law enforcement agencies undertaken by President Barack Obama’s Justice Department.

The findings come just a week before Donald Trump is sworn in as president, marking a change from a Democratic White House that has strongly backed the review process to a Republican one that has expressed far less support for federally mandated overhauls of troubled police agencies.

The Justice Department began investigating the police force in December 2015 after the release of dashcam video showing a white officer shooting black teenager Laquan McDonald, who was hit 16 times as he held a small folded knife while walking away from police. The video of the 2014 shooting, which the city fought to keep secret, inspired large protests and cost the city’s police superintendent his job.