In a chilling case unfolding in Wisconsin, a 38-year-old man is accused of committing a heinous crime against his pregnant girlfriend and her pet dog. Authorities allege that Matthew R. Sierra took the life of 27-year-old Alexis Pickett, along with her unborn child, before setting her residence ablaze.

Sierra faces a slew of grave charges, including first-degree intentional homicide, the intentional homicide of an unborn child, arson, and animal mistreatment resulting in death. This tragic incident has left the community in shock and mourning.

The grim discovery was made early on November 13, when the La Crosse Fire Department responded to reports of a house fire on the 1700 block of Taylor Street. Upon arrival, firefighters were met with thick smoke and, tragically, found Pickett deceased inside her home.

Crucial details emerged after Law&Crime accessed a criminal complaint. The autopsy results revealed that Pickett had died prior to the fire, as evidenced by the absence of soot in her lungs and low levels of carbon monoxide in her system. The cause of her death remains undisclosed. Authorities confirmed that her dog had also been killed before the flames engulfed the home, with its body discovered beneath a toilet.

Surveillance footage played a pivotal role in the investigation. It captured Sierra arriving at Pickett’s residence around 12:45 a.m. and departing approximately two hours later. Notably, smoke alarms were heard blaring as Sierra was seen leaving in his vehicle, painting a haunting picture of the night’s events.

Sierra and Pickett already had a child together and she was pregnant with their second child. But he wanted her to have an abortion and threatened to seek custody of their first child if she refused, cops alleged.

Detectives spoke with Pickett’s friend, who said, “All I know is that they have been on and off and they have been constantly fighting because he found out she was pregnant with his kid and he didn’t want anything to do with it.”

The defendant claimed he was at a gas station at the time of the fire, but cellphone data showed he was at Pickett’s home.

Cops arrested Sierra on Tuesday and took him to the La Crosse County Jail, where he remains on a $1 million bond. His next court date is set for Dec. 23.

“This has been a very diligent, comprehensive, and strategic investigation in collaboration with the La Crosse Fire Department and the Wisconsin Department of Justice Division of Criminal Investigation and the Wisconsin State Fire Marshal’s Office,” City of La Crosse Police Chief Shawn Kudron said in a statement. “Our thoughts continue to be with the Pickett family.”

Sierra is a mechanical design professor at Western Technical College, according to local ABC affiliate WXOW. He was placed on administrative leave.