OAKLAND, Calif. (KRON) — An Oakland man was identified on Tuesday who, according to investigators, may have been the first victim of a possible California serial killer.

Juan Miguel Vasquez Serrano, 39, of Oakland, was slain on Harmon Avenue at 4:18 a.m. on April 10, 2021, an Alameda County Sheriff’s Office spokesperson told KRON4. Serrano died from gunshot wounds at the scene. The Oakland Police Department was alerted to the shooting by its ShotSpotter gunshot audio detection system, but when officers arrived, the killer had already slipped away.

Stockton police said they uncovered evidence linking Serrano’s killer with recent serial killings in their city. Detectives believe that one person likely carried out six shootings in Stockton, targeting victims who walk alone down dark, empty sidewalks. Five of the six Stockton victims were fatally shot.

Stockton Police Chief Stanley McFadden said, “Our investigators have reviewed many hours of video surveillance. They believe they located a ‘person of interest’ in this investigation. These homicides occurred in the evening or early morning hours and our victims were alone.”

stockton serial killer
The Stockton Police Department released this surveillance image of a “person of interest.”

Police released a grainy black and white surveillance image of the “person of interest.”

“It definitely meets the definition of a serial killer,” officer Joseph Silva told KTXL. “What makes this different is the shooter is just looking for an opportunity. Our victims were alone in a dark area.”

McFadden urged Stockton residents to be vigilant while the person is still at-large.

“We would like to remind everyone to remain vigilant and have good situational awareness. Please avoid isolated areas and travel in well-lit areas. Remember, there is safety in numbers so if you can, travel with a friend,” McFadden said.

All of the Stockton homicide victims were Hispanic men, except one, according to police. The victims’ ages ranged between 21-54.

As far as a motive, police did not believe the serial killings were hate crimes, gang-related, nor robberies. None of the victims were robbed.

Police did not say how they connected the Oakland homicide to the killings in Stockton, about 70 miles east.

A $100,000 reward is being offered for information leading to an arrest. Reward money was raised through the City of Stockton, Stockton Crime Stoppers, and anonymous business owners.

McFadden wrote in a message to the public on Facebook, “We are committed to protecting our community and solving these cases utilizing all the resources at our disposal including YOU. We need YOUR help!!!! If anyone has information regarding these investigations, call us immediately. Please remember our victims have grieving family members who need resolution. If you know something, say something.”

Police setup a tip line at 209-937-8167. You can also email information to policetips@stocktonca.gov, or submit video surveillance to stocktonpdca.evidence.com/axon/citizen/public/tips2022 . Stockton Crime Stoppers can be contacted at 209-946-0600 or stocktoncrimestoppers.org

Serial killing victims

April 10, 2021: Juan Miguel Vasquez Serrano, 39, of Oakland was shot on Harmon Avenue at 4:18 a.m.

July 8, 2022: A white man was gunned down on the 5600 block of Kermit Lane at 12:31 a.m.

August 11, 2022: A 43-year-old Hispanic man was fatally shot on the 4900 block of West Lane at 9:49 p.m.

August 30, 2022: A 21-year-old Hispanic man was slain by a gunman on the 800 block E. Hammer Lane at 6:41 a.m.

September 21, 2022: A 52-year-old Hispanic man was shot on the 4400 block of Manchester Avenue at 4:27 a.m.

September 27, 2022: A 54-year-old Hispanic man was shot on the 900 block of Porter Avenue at 1:53 a.m.