Phoenix detectives were assembling a jigsaw puzzle of sorts in the past month, piecing together witness statements and physical evidence to mount a nine-victim homicide case against 35-year-old Cleophus Cooksey Jr.

The key information was gleaned just two days after Cooksey’s Dec. 17 arrest in the deaths of his mother and stepfather, leading police to believe he was not just a double-murder suspect but a serial killer.

Since mid-2017, the Phoenix police department has been using high-powered in-house technology to compare bullet casings from multiple crime scenes. Investigators previously had to run the technology outside of the department, which could tack weeks onto an investigation. 

The result is near-instant leads for police, Phoenix Mayor Greg Stanton told AZCentral.

The technology was obtained through a $1 million grant from the U.S. Department of Justice. In 2016, the DOJ’s Bureau of Justice Assistance awarded funding to allow Phoenix to create a regional crime gun intelligence center. Similar grants were awarded to Los Angeles, Milwaukee, Washington, D.C. and Kansas City and are part of the National Crime Gun Intelligence Center initiative.