ST. CHARLES COUNTY, Mo. – A Missouri man will spend the rest of his life in prison for a brutal attack in 2014 that claimed the lives of three people, including a 7-year-old boy.

After a three-day bench trial, St. Charles County Circuit Court Judge Rebecca Navarro-McKelvey convicted Shawn Kavanagh on March 17 on nine counts connected to the murders: three counts of first-degree murder, four counts of armed criminal action, one count of first-degree domestic assault, and one count of first-degree burglary.

On Tuesday, April 11, Navarro-McKelvey sentenced Kavanagh to life in prison without the possibility of parole or probation for each count of murder, 15 years on each count of armed criminal action, life imprisonment for domestic assault, and 15 years for the burglary. The sentences will be served consecutively.

On the evening of Feb. 14, 2014, Kavanagh called 911 to say he’d stabbed four people inside a trailer home in Warren County. Two of the victims, 22-year-old Tara Fifer and 29-year-old Lexy Vandiver, died in the attack. A third victim, 7-year-old Mason Vandiver, died days later at the hospital. The fourth victim, Kavanagh’s soon-to-be ex-wife, was visiting Fifer’s home at the time of the attack. She survived.

According to court documents, Kavanagh went to the trailer and accused his ex-wife—they were only separated at the time—of being involved in a romantic relationship with one of the other victims. The couple got into an argument, and Kavanagh left the trailer to retrieve a knife from his car. He returned to the trailer and began stabbing the women.

Prosecutors said the four victims had been stabbed a total of 75 times, and that Kavanagh stabbed Mason when the boy tried to protect his mother.

Kavanagh remained at the trailer after calling 911 and was arrested. Law enforcement said Kavanagh wanted to spend Valentine’s Day with his then-wife, and got angry seeing her with one of the other victims.

While the murders happened in Warren County, the trial was moved to St. Charles County because of a defense request for a change of venue. The Warren County Prosecuting Attorney’s Office had sought the death penalty in the case. The Missouri Attorney General’s Office assisted in the prosecution.

Public defenders argued Kavanagh suffers from mental disorders and asked his charges be reduced to second-degree murder, which would have made him ineligible for the death penalty.

Kavanagh waived his right to a jury trial and asked Navarro-McKelvey to decide his fate.

According to our news partners at the St. Louis Post-Dispatch, Navarro-McKelvey acknowledged the victims’ families would not be happy with her decision.

Warren County Prosecuting Attorney Kelly King said she respected the judge’s verdict, but was disappointed with the sentence.

“I can only hope the families can now put this part of these horrific crimes behind them and move forward with their lives,” she said. “I sincerely appreciate the work of our first responders, the assistance of the Attorney General’s Office, and the cooperation and patience of the victims’ families. Without their efforts, we could not have prosecuted this case. As disappointing as the verdict is, Mr. Kavanagh will spend the rest of his life in prison.”