Five Atlanta gang members were convicted this week of raping and killing a man that was a former police informant. Prosecutors are calling it  “the most brutal murder” in the city’s recent history.

The men — all purported members of the Gangster Disciples street gang — murdered Christopher Dean, 33, in October 2016 after they discovered that he was once a police witness in California.

Christopher Lockett, 30, had invited the victim to the home of brothers Xavier Gibson, 23, and Orlando Gibson, 30. The victim was told that he could buy drugs at the location, the Fulton County District Attorney’s Office said in a statement.

But instead, Dean was brutally beaten with a two-by-four and a crowbar and sodomized with a handle-like object — and seminal fluid was discovered in his rectal cavity, prosecutors said. The savage crew then allegedly shot Dean twice in the back of the head.

Lockett, Xavier Gibson, Quatez Clark, 21, Joshua Rooks, 27, and Jasper Green, 27, were convicted Monday of murder, participation in criminal street gang activity and other related felonies, according to prosecutors.

Rooks then picked up Green and Lamar Almon, and the three returned to the scene of the murder where Lockett paid Almon and Green to “clean up brain matter and blood from the scene of the murder and to burn the victim’s body and his car,” the DA’s office wrote.

Originally, the perpetrators were going to burn Lockett’s car with Dean’s body inside, but Green and Almon decided to leave the car and Dean’s body in the trunk.

Atlanta police discovered the body, and seven suspects were arrested, the DA’s office said.