Baltimore Prosecutor Marilyn Mosby Joins Prince On Stage at ‘Rally 4 Peace’

State’s Attorney Marilyn Mosby appeared onstage at Prince’s “Rally 4 Peace” in Baltimore on Sunday night as attorneys for the six police officers charged in the death of Freddie Gray have questioned the prosecutor’s impartiality in the case.

Prince’s concert–his first in the city in 14 years–was organized in remembrance of Gray, who died of a spinal cord injury last month while in police custody. The pop icon had urged attendees to “wear something gray” to the show.

At the beginning of his set, Prince played his newly-released song “Baltimore,” a tribute to Gray and Michael Brown that includes the refrain “if there ain’t no justice, then there ain’t no peace.”

According to the Baltimore Sun, Prince invited Mosby to join him onstage during the performance of “Baltimore,” where she waved to the audience but did not address them. A spokeswoman for Mosby told the Sun that the concert tickets were a Mother’s Day gift from her husband, Councilman Nick Mosby.

Mosby’s onstage appearance comes as attorneys for the six Baltimore police officers charged in the death of Gray have filed a motion to remove her office from the case. The attorneys claim Mosby has several conflicts of interest, including that she accepted campaign money from Gray’s family attorney, and that she and her husband stand to gain politically and financially from future court proceedings.

Mosby has also come under fire for the speed with which she announced the charges against the six officers. Last week, the Sun reported that two of the names and addresses of the charged officers were incorrect, leading journalists and others to harass innocent people. Wicomico County Sheriff Mike Lewis said last week that the mistake was “a direct result of a hasty prosecutor who wants to charge these individuals.” Michael Davey, an attorney for the Baltimore Fraternal Order of Police, characterized the charges as politically motivated.

At the concert, Prince reportedly kept his stage remarks short as he played through several of his classic hits, including “Little Red Corvette” and “When Doves Cry.” The streaming music service Tidal carried the first half of the concert for free online.

“The system is broken. It’s going to take the young people to fix it this time,” he said at one point. “We need new ideas, new life. … The next time I come to Baltimore I want to stay in a hotel owned by you.”

Outside, a small group of protestors reportedly handed out literature from the Revolutionary Communist Party and urged attendees to continue to push for social justice. One of the protesters, Noche Diaz, told the Sun that public pressure led Mosby to file charges against the officers.

“We’re here to remind people that just because there are charges, there’s not justice,” Diaz told the paper. “People can celebrate tonight, but the fight has to continue.”