Police investigating five fatal shootings in California believe a serial killer could be on the loose in the state.
Detectives released a grainy image of a “person of interest” after the latest murder just before 2am on Tuesday.
The surveillance footage image shows an individual from behind who is dressed all in black, with a black hat.
Stockton police said they could be a suspect or a witness.
Rewards totaling $ 85,000 (£ 76,000) are offered for information leading to an arrest after the shootings.
Stockton Police Chief Stanley McFadden said the latest victim was a 54-year-old man who was shot dead in a residential area.
He was the fifth man fatally shot since July 8 within a few square mile radius in Stockton.
Mr. McFadden also provided details of each of the attacks that took place.
• July 8 – An unidentified 35-year-old man described only as white was shot dead at 12:31 am
• August 11 – An unidentified 43-year-old man described as Hispanic was killed at 9:49 pm
• August 30 – An unidentified 21-year-old man described as Hispanic was shot dead at 6:41 am
• September 21 – An unidentified 52-year-old man described as Hispanic was killed at 4:27 am
• September 27 – An unidentified 54-year-old man described as Hispanic was fatally shot at around 1:50 am
“Be careful: keep your head on a swivel”
McFadden said he believes all five murders are related “based on our investigation and the reports we are receiving.” All the victims were walking alone when they were killed.
Stockton is a city of 320,000 residents approximately 50 miles (80 km) south of the state capital of Sacramento.
McFadden said police have ruled out gang violence, hate crime and targeting homeless residents, with investigators still unable to determine if there are one or more shooters.
The police chief wrote on Facebook: “We are committed to protecting our community and solving these cases, using all the resources at our disposal including YOU. We need YOUR help !!!! call us immediately.
“Please remember that our victims have grieving family members who need a solution. If you know something, say something.”
McFadden added that the killings took place in “dimly lit” areas “obscured by trees”.
“Be careful,” he said. “Put your head on a swivel.”
The City of Stockton offered a reward of $ 75,000 (£ 67,000) and Stockton Crime Stoppers offered an additional $ 10,000 (£ 8,884).
