BALTIMORE — With just days until Donald J. Trump is sworn in as president, the Obama administration is making a last-minute push for police overhauls in two of the nation’s most violent cities, Baltimore and Chicago, where officers have been accused of routinely mistreating African-Americans.

In Chicago, where a city task force appointed by Mayor Rahm Emanuel concluded that “the police have no regard for the sanctity of life when it comes to people of color,” the Justice Department is rushing to wrap up a sweeping investigation into police patterns and practices, prompted by the release of a chilling video that showed a white officer shooting a black teenager. The findings are expected to be released before Jan. 20, Inauguration Day.

Such an investigation is typically the first step toward a consent decree in which a police department is required to make significant changes under court supervision. But in Chicago, President Obama’s Justice Department is running out of time to pursue such an order, and activists fear that the Trump administration will abandon the effort.

Here in Baltimore, where Justice Department officials have already released a blistering report accusing the police of systematic racial bias, negotiators for the city and the Obama administration are “getting very close” to agreement on a consent decree, Mayor Catherine E. Pugh said. An announcement is likely on Thursday; the United States attorney general, Loretta E. Lynch, is scheduled to deliver a speech on community policing at the University of Baltimore.