Baltimore Mayor Stephanie Rawlings-Blake is now asking the Justice Department to investigate the city's police department.

She also promised that officers would wear body cameras by next year. 

The announcement comes a day after Attorney General Loretta Lynch visited the city.

Rawlings-Blake said the DOJ would be looking into "systemic challenges" that contribute to police using excessive force or discriminating. 

"I'm asking the Department of Justice to investigate if our police department has engaged in a pattern or practice of stops, searches or arrests that violate the Fourth Amendment," she said.

Judge Andrew Napolitano gave us his reaction to the new developments this morning, calling Rawlings-Blake's announcement a "bit of a head-scratcher."

Napolitano said there's already a criminal investigation going on, including a murder charge against one police officer in the Freddie Gray case.

He said if the DOJ conducts the investigation, it will be similar to the probe of the Ferguson, Missouri, police department. 

The judge also pointed out that it's unusual for local authorities to ask the feds to come in and investigate their police department. 

Napolitano then discussed one of the key pieces of evidence in the Gray case: a knife that was being carried by Gray at the time of his arrest. 

An attorney for one of the officers charged in Gray's death is demanding that prosecutors let him see the knife.

Watch his full analysis above.