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Price Motel crime scene

Police investigators work the crime scene at the Price Motel on East North Street on March 8.

A 24-year-old man was sentenced Monday to 70 years in prison for the fatal stabbing of his roommate at a Rapid City motel last year. He and the victim apparently grew up in the same foster family.

Vincent Mousseaux had pleaded guilty to first-degree manslaughter in the killing of 30-year-old Deziree Martinez at the Price Motel on March 8.

The prosecution asked 7th Circuit Judge Jeff Connolly for a life sentence, the maximum penalty for the crime. The defense asked for a “reasonable sentence.”

“He took a life, so the state felt life was in order,” the prosecutor, South Dakota Assistant Attorney General Scott Roetzel, said in an interview.

He highlighted the violent nature of Martinez’s killing, saying at least 40 stab wounds and about 30 cuts were found all over her body. An autopsy found she died of a stab wound to the lung.

Roetzel said the attack was fueled by alcohol, at a time when Mousseaux was on probation for a 2016 burglary-related offense and had been forbidden from drinking.

Mousseaux was initially arrested on a probation hold, about a mile away from the motel, a few hours before Martinez’s body was discovered. His blood alcohol level had been more than three times the legal limit for driving.

Police found Martinez's body at the motel, located on East North Street, after a passerby saw her lifeless through her open motel room door. She had six children.

Defense attorney John Murphy told the court that Mousseaux suffered from untreated mental health issues.

At age 8, Mousseaux was injured in a car accident that killed both his parents. Medical professionals recommended counseling, which Mousseaux apparently never received.

He and his sister, together with Martinez and her brother, were placed in foster care that turned out to be “dysfunctional,” Murphy said in an interview. Mousseaux and Martinez grew up together and thought of each other as cousins, Murphy added.

His sister also said Mousseaux had been diagnosed with schizophrenia, which went largely untreated.

Investigators said Martinez, Mousseaux and another man, Hawk Chavez Sr., had been hanging out at the motel room when an argument between Martinez and Mousseaux broke out.

Mousseaux reportedly tried to stab Martinez when Chavez stepped in to defend her. Mousseaux attempted to stab Chavez, but he took the knife from Mousseaux, who then grabbed another knife and chased him from the room. He then came back for Martinez.

Mousseaux was originally charged with alternate counts of first-degree murder and second-degree murder, as well as aggravated assault against Chavez. The charges, along with a new one of simple assault against a jail correctional officer, were dismissed in accordance with Mousseaux's plea agreement with prosecutors.

He was given credit for 341 days served in county jail, and will be eligible for parole after about 60 percent of his prison sentence has been served. He would be in his 60s at that time.

Martinez’s killing was one of seven homicides in Rapid City in 2017. Three of the eight defendants have now been sentenced, including a man who received life in prison without the possibility of parole for a January 2017 stabbing at the Dakota Rose Inn.

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Cops and Courts Reporter

Cops and courts reporter for the Rapid City Journal from February 2016 to July 2018. Contact her on Facebook or Twitter @tiffgtan.