Did an Illinois firefighter have a secret he was willing to kill for?

On Nov. 25, 2020, the day before Thanksgiving, responders rushed to a house fire in Mt. Morris, Illinois. They discovered 27-year-old Melissa Lamesch inside, dead on the floor by the oven in the kitchen.

Initially, investigators were uncertain whether the fire was intentional or accidental. But after taking a closer look, they believed foul play was involved and that the fire was arson. They did not find any electrical issues at the house and learned that the oven and stove burners were all in the off position. The autopsy performed on Lamesch revealed no soot in her lungs and normal carbon monoxide levels, but there were signs of strangulation. Investigators concluded that Lamesch was murdered before the fire started. But why would someone want to kill Melissa Lamesch?

“48 Hours” contributor Nikki Battiste reports on the case in “The Firefighter’s Secret.”  An encore of the episode airs Saturday, Jan. 31 at 9/8c on CBS and streaming on Paramount+.

When the fire occurred, Lamesch had been just two days away from giving birth to a baby boy. She was a dedicated EMT and was excited to become a parent. However, investigators learned there was someone who was not as enthused – the expectant father of the baby, 33-year-old Matthew Plote, who was a firefighter-paramedic.

When Lamesch let Plote know she was carrying his baby, she was surprised by his reaction, says Lamesch’s sister, Cassie Baal. “Melissa thought he would want something to do with the baby. To that point, she thought he was a pretty nice guy,” Baal told “48 Hours.” “She saw a different side of him and that really upset her.”

Investigators learned Plote kept the fact that he was going to become a dad a secret, including from his parents and his co-workers. Rob Schultz, fire chief at the Carol Stream Fire District where Plote worked, explained to Battiste how unusual it was for someone not to talk about a big life event at the firehouse. “We’re here 24 hours a day,” Schultz said. “It’s a — just a normal, uh, course of being a firefighter … that you talk about your family, your personal life, and what’s going on good, bad or indifferent.”

Although Plote seemed disinterested in becoming a father, Lamesch had sporadically kept in touch with him, even sending him sonograms. “Sometimes he would respond a little bit, but she didn’t know really where he stood exactly,” Baal said.

Lamesch, though, was ready to take care of the baby on her own, with the help of her family. Despite Lamesch not asking Plote for any type of support, investigators believe that as her due date drew closer, Plote became increasingly concerned that having a child was going to alter his lifestyle and that’s why he had kept that baby a secret.

“He was keeping a secret — the fact that he fathered a baby in the hopes that the child wouldn’t be born,” Ogle County Assistant State’s Attorney Allison Huntley told Battiste.

The state began building a case against Plote. He was arrested on March 9, 2022, on charges including murder, the intentional homicide of an unborn child and arson.

There was evidence that Plote had been at Lamesch’s house the day of the fire – something Plote admitted when he spoke with investigators. “He told them everything … about his presence there, he didn’t hide any of that,” defense attorney John Kopp told “48 Hours.” He says his client went there to discuss plans for being involved in the baby’s life. “They discussed their finances,” Kopp said. “And then Matt left as she was making some lunch.”

Prosecutors suspected Plote was lying about Lamesch being alive when he left and that he set the house on fire to try to cover his tracks. “I believe from the very beginning he was trying to set up a story that there was an accidental house fire, that she had been cooking something,” said Ogle County Assistant State’s Attorney Heather Kruse. “Which would explain why her body was found in the kitchen.”

For Chief Schultz, the thought of a firefighter inflicting harm was unthinkable. “It doesn’t chime with what a firefighter is,” he told “48 Hours.” “We put fires out. We don’t start fires. We help people. We don’t hurt people.”