A Baltimore homicide detective was killed with his own service weapon as he was preparing to testify against fellow officers indicted in a drug-running scheme.

Sean Suiter, 43, was fatally shot in the head on Nov. 15 and authorities said there was evidence of a struggle, The Baltimore Sun reported on Wednesday.

Suiter was scheduled to testify before a federal grand jury about a case that alleged cops in his city had conspired with officers in Philadelphia to sell cocaine and heroin seized from the streets of Baltimore, according to Philly.com.

Baltimore Police Commissioner Kevin Davis said authorities have no reason to believe Suiter’s killing was connected to his pending testimony, according to The Baltimore Sun.

“The BPD and FBI do not possess any information that this incident … is part of any conspiracy,” Davis said.

Commissioner Davis said authorities are offering a $215,000 reward for information leading to an arrest in Suitor’s killing, the Sun reported.