Joseph Charles Mantynen accepts a plea of 26 years, 4 months

A homicide case filed last December against defendant Joseph Charles Mantynen was resolved this afternoon in the Mendocino County Superior Court.



Defendant Joseph Charles Mantynen, age 32, of Hidden Valley, plead guilty to an amended count charging voluntary manslaughter, a felony; a count charging an assault with a firearm on a Mendocino County deputy sheriff, a felony; a  count charging a separate assault with a firearm but on a Sonoma County deputy sheriff, a felony; and a count charging burglary in the first degree, a felony. The defendant also admitted that he had personally used a firearm in the commission of the conduct underlying the conviction for voluntary manslaughter.

Defendant Mantynen and an accomplice, his parolee wife, together burglarized the home of Mantynen's grandmother in Sonoma County on December 20th. Investigators from the neighboring county tracked the couple to Ukiah and found them hiding out in a State Street motel on December 21st. Rather than surrender, Mantynen later confessed to interrogators that the couple had agreed to resist arrest and, if escape was not in the cards, to die together by means of "suicide by cop."

During the early stages of the stand-off, Mantynen pointed his rifle at and threatened a Sonoma County deputy sheriff. In doing so, Mantynen committed what is known in the law as a provocative act that allowed for the use of deadly force by the threatened deputy. Fearing for his own safety and that of his team, the Sonoma County deputy discharged his firearm at Mantynen but the shot missed the provocateur.

The out-of-county law enforcement officers surrounding the motel room were quickly reinforced by the Ukiah Police Department, as well as the Sheriff's special weapons and tactics unit. As the stand-off lengthened, Mantynen again pointed his rifle at and threatened law enforcement, this time a Mendocino County deputy sheriff.

Apparently as part of the couple's death plan, this act by Mantynen was provocative that allowed for the use of deadly force by the local deputy.

Fearing for his own safety and that of others, the Mendocino County deputy discharged his firearm at Mantynen. That shot went through Mantynen's bulky clothing, missing the defendant's body, hitting the defendant's wife, who was also participating in the stand-off and verbalizing death threats at law enforcement. After his wife was fatally hit and fell to the ground, Mantynen  surrendered to the law enforcement presence.

Following his review of crime reports from the multiple agencies, the Mendocino County District Attorney elected to charge the defendant with being responsible for the death of his wife pursuant to the "provocative act" doctrine.

This doctrine is a legal theory of homicide prosecution which applies when someone commits an act that provokes someone into killing someone else.

Pursuant to today's resolution, as worked out by the defendant, his attorney, and District Attorney Eyster, Mantynen will be sentenced to a stipulated commitment on March 28th of 26 years, 4 months in state prison.

Because of the violent characterization of the crimes involved, the good time/work time credits the defendant may earn in prison against his total sentence will be limited to 15%.  The District Attorney also required that Mantynen waive all jail credits from the date of his arrest until the date of sentencing.

The prosecutor handling this matter will continue to be District Attorney David Eyster.

The investigating law enforcement agencies are the Sonoma County Sheriff's Department, the Mendocino County Sheriff's Department, the Ukiah Police Department, the California Department of Justice forensic laboratory, and the District Attorney's own investigators.

 The judge who accepted today's change of plea was Mendocino County Superior Court Judge John Behnke.  Judge Behnke will formally sentence the defendant to the aforementioned prison sentence on March 28, 2018 at 9 o'clock in the morning in Department H of the Ukiah courthouse.