An Arizona jury found Cleophus Cooksey Jr. guilty of eight 2017 murders, making him one of the state’s most prolific serial killers, with the sentencing phase for potential death penalty expected to continue until December.

Over three weeks in late 2017, Cooksey killed nine people in scattered locations throughout Phoenix, using theft, revenge, and other personal motives, though one suspected victim was not charged.

He was arrested in December 2017 at his mother’s home with blood on his hands, and police linked him to multiple shootings using ballistics, DNA, cell phone records, and GPS evidence.

Cooksey’s attorneys argued that the ballistic evidence was unreliable, but prosecutors presented a broader pattern tying him to the killings, USA Today has reported.

Victims’ families reacted emotionally to the verdict, and prosecutors emphasized Cooksey’s central role in the murders despite not offering a motive for each individual crime.