VALLEJO – A Vallejo police detective who was once fired for the fatal shooting of Sean Monterrosa in 2020 has been promoted to sergeant, according to a department roster released this week.
It is not clear from the roster what date Sgt. Jarrett Tonn was promoted, but it was within the last two months. The Vallejo Sun obtained the roster through a public records request.
Tonn had taken the sergeant’s exam earlier this year and Vallejo councilmembers were alerted that he was likely to be promoted, according to a source with knowledge of the communications. The Vallejo Police Department did not respond to a request for Tonn’s promotion date and current assignment.
The promotion is the latest in a remarkable reversal of fortune for Tonn, who was fired for the Monterrosa shooting but returned to work in 2023 after an arbitrator overturned that decision and ordered Tonn to be reinstated.

Tonn shot and killed 22-year-old Monterrosa during looting incidents on June 2, 2020. He and two other officers were pulling into a Walgreen’s parking lot as looters fled the building, and Tonn shot Monterrosa with a high-powered rifle through the windshield. Monterrosa was shot in the back of the head.
Immediately after the shooting, Tonn claimed that he saw Monterrosa with a gun, but Monterrosa only had a roofing hammer in the pocket of his hoodie.
His reinstatement drew protests at the time, and civil rights attorneys said they would hire a security detail to monitor Tonn’s movements.
The state Department of Justice cleared Tonn of any criminal wrongdoing in the Monterrosa shooting after a three-year investigation. A civil lawsuit brought by Monterrosa’s family is still pending, and the city lost a motion for summary judgement in the case earlier this week.
Monterrosa was Tonn’s fourth on-duty shooting in Vallejo.
His first shooting in Vallejo happened less than a year after he was hired. On Feb. 22, 2015, Tonn and Officer Gary Jones chased the driver of a stolen vehicle. After the driver stopped, he allegedly put the car in reverse and struck Tonn and Jones’ patrol car. Tonn fired 18 times and Jones fired once, wounding Brown.
Tonn was one of several officers who fired on a wanted carjacking suspect, Kevin DeCarlo, on May 31, 2017. DeCarlo allegedly rammed the driver’s side of a police truck. Tonn and two other detectives fired into the car. DeCarlo was wounded but survived.
Tonn fired his weapon again a little more than a month later, on July 8, 2017, at a fleeing carjacking suspect but missed. Tonn claimed that he saw the man running away with a gun, but while the man was later arrested, no gun was ever found.
Last year, the American Civil Liberties Union submitted a complaint to the California Commission on Peace Officer Standards and Training seeking to de-certify nine current and former Vallejo police officers, including Tonn. The complaint stated that all nine “have been alleged to commit serious misconduct in the use of deadly force that resulted in death or serious bodily injury.”
Vallejo police have a pattern of giving promotions and awards to officers who have used force or been involved in allegations of civil rights violations. A 2021 analysis showed that two-thirds of officers who were involved in incidents that led to settlements and payouts received a promotion or award after.
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THE VALLEJO SUN NEWSLETTER
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Scott Morris
Scott Morris is a journalist based in Oakland who covers policing, protest, civil rights and far-right extremism. His work has been published in ProPublica, the Appeal and Oaklandside.
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