Officers charged in the death of a black man whose neck was broken in the back of a police van are asking a federal appeals court to allow parts of a lawsuit against Baltimore’s top prosecutor to proceed.

The officers are suing State’s Attorney Marilyn Mosby for malicious prosecution, defamation and invasion of privacy. Three of the officers were acquitted, and Mosby dropped the remaining cases.

Mosby says the lower court should have found her to be immune from being sued because she’s a prosecutor.

But the officers said in a brief filed Thursday with Virginia’s 4th U.S. Circuit Court of Appeals that Mosby isn’t entitled to immunity because she was acting as an investigator, not a prosecutor.

Freddie Gray died in 2015, a week after his neck was broken.

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