Was Person X interviewed before Person Y? Did the detectives have Forensic Report A when they talked to Suspect B? Find that information and more right here.
Multiple victims or only one?
Examine the relevant case files
Investigation Day 3 — The local press is on the story of the human body parts discovered in Yoknapatawpha and surrounding counties.
Throwing around the words "serial killer" may get them more readers, but don't believe everything you read.