Denver judge sentences man to life in prison for murdering mother of his children
A Denver judge sentenced a Wisconsin man to life in prison without the possibility of parole for murder. Angelo Mantych was convicted of murder by a jury on Dec. 12, 2025 for the death of the mother of his children.
According to prosecutors, Mantych killed 28-year-old Marina Placensia on board the train they were riding from Wisconsin to Denver. Placensia and Mantych had three young children together, all of whom were on board the train when she was killed.
"Marina Placensia's death was a horrifying tragedy: a young mother with her whole life ahead of her smothered to death while her children slept nearby. Today's sentence ensures that Angelo Mantych will spend the rest of his life in prison, where he belongs after committing such a heinous crime. I hope this sentence brings some comfort and a sense of justice to all those who knew and loved Marina, most importantly, of course, her children," said Denver District Attorney John Walsh in a statement. "I want to thank the prosecutors, investigators, victim advocates and paralegals in my office whose outstanding work over many years brought about the successful resolution of this case."
Investigators said that on Aug. 30, 2016, Placensia, her four children- three of whom she shared with Mantych- and Mantych boarded an Amtrak train in Wisconsin, where they lived, and headed for Denver. When the train arrived at Denver's Union Station on Sept. 1, 2016, Placensia was dead.
After several years of investigation, prosecutors charged Mantych with causing Placensia's death on the train in October 2023. He was convicted last month and sentenced to life in prison on Friday.
