Man who killed wife trying to escape to Colorado convicted almost 10 years after her murder

After almost 10 years, a Wisconsin man who killed his wife on an Amtrak train to Denver back in 2016 has been convicted of her murder. 

Investigators ultimately determine Angelo Mantych suffocated his wife, 28-year-old Marina Placensia, to death, and he was found guilty by a jury in court on Friday.

On August 30, 2016, Placensia and Mantych, who is now 45, and Placensia's four children -- three of whom are also Mantych's -- boarded a train heading from their home in Wisconsin to Denver. The Denver District Attorney's Office said that, by the time the train reached Union Station on Sept. 1, Placensia was dead.

According to court documents, Mantych told police that his wife was sleeping, and he tried to wake her before the train arrived. Mantych claimed that when Placensia didn't respond, he asked for help.

The investigator who responded to the call said he noticed "numerous bruises on the body that appeared consistent with an assault or struggle," but that none would be an obvious cause of death. Mantych told the investigator that she was "banged up from moving" and that a screen door had hit Placensia, and the other bruises were from moving heavy furniture down the stairs.

However, Placensia's brother warned authorities that Mantych was abusive. Police in Racine, Wis., confirmed Mantych had previously been arrested and charged with physical abuse against her.

A former neighbor also told family members that Mantych physically abused Placensia the day before the couple left, and that he had done so multiple times in the past. One of her friends told investigators that she was speaking with family members about moving back to Colorado to get her away from Mantych, and that he had threatened to kill her and her children if she left him.

Reports said that, although she had 35 internal and external injuries, none of them were severe enough to explain her death. Officials also ruled out Placensia's liver disease as a potential cause, which was revealed in her autopsy.

It wasn't until 2022 that an expert on strangulation and suffocation was brought in to review the case. In 2023, the expert assigned told District Attorney Maggie Conboy that he determined Placensia's cause of death to be "suffocation and the manner as homicide."

Based on the findings and conclusion, an arrest warrant was made for Mantych. He was arrested and charged with first-degree murder for Placensia's death.

Mantych was convicted Friday afternoon, and he now faces life in prison without the possibility of parole. His sentencing will be held on Jan. 9, 2026.