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Report: 'Deadly force was not objectively reasonable' after Vallejo officer killed Sean Monterrosa during protests

Described by private investigators as the key issue they examined for the report, Officer Jarrett Tonn was found to have used unnecessary force in the confrontation.

VALLEJO, Calif — A recent 66-page independent report for the June 2, 2020, Vallejo police killing of Sean Monterrosa found the use of "deadly force was not objectively reasonable."

The 22-year-old Sean Monterrosa was spotted by officer Jarrett Tonn — who was not specifically named in the new report but previously identified by the Vallejo Police Department — kneeling in front of a Walgreens amidst the 2020 summer nationwide protests against the police killing of George Floyd.

Sitting in an unmarked police cruiser with a rifle just outside the Walgreens, Tonn hit Monterrosa once in the back of the head, out of the five bullets the officer shot through his windshield. Tonn said at the time he thought Monterrosa was reaching for a gun to harm him or his patrol partner. After he was killed, no gun was found, only a hammer in Monterrosa's pocket.

Private investigators with the independent police review agency OIR Group were contracted to review the incident soon after the incident. In their report released on Thursday, investigators reported Tonn violated his department's use-of-force policy.

The policy states "imminent threat of death" or serious injury exists for the officer when another reasonable officer in the same situation would could come to the same assessment.

But Tonn failed to employ de-escalation techniques and provided a "tactically poor" response, according to the report.

"Because of these factors, the chances of a non-threatening — or even capitulating — movement by Mr. Monterrosa being misperceived as a deadly threat were greatly increased," wrote investigators Michael Gennaco and Stephen Connolly. "The (Vallejo) detectives' approach left no margin for error."

Additional video never previously shown from the June 2, 2020, killing was also released by the city of Vallejo.

While the recent report is separate from the review into Vallejo PD's investigation announced in May by California Attorney General Rob Bonta, Vallejo Police Chief Shawny K. Williams said the city-commissioned investigation provides the community more transparency through the ongoing investigations.

“My objective in launching this third-party independent investigation was to determine the exact events of that night and to determine if the officers’ actions were consistent with department policy,” Williams said. “A life has been lost, and I want our community to know that the City and the department are committed to being open, fair and transparent throughout the investigative process."

Williams did not announce any additional action against Tonn, though he remains on administrative leave since June.

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