LA CROSSE, Wis. (Court TV) — Prosecutors have refiled charges against a college professor in Wisconsin accused of murdering his pregnant mistress and setting her home on fire.
Matthew Sierra, 38, was initially charged with two counts of first-degree intentional homicide, arson and mistreatment of animals causing death, according to a news release. The charges were dismissed at a hearing on Dec. 23, and prosecutors were given 72 hours to refile.
On Dec. 26, prosecutors filed charges of first-degree intentional homicide, first-degree intentional homicide of an unborn child, arson of a building and mistreatment of an animal causing death.
Matthew Sierra (L) and Alexis Pickett (R). (City of La Crosse, Wisc.)
Alexis Pickett, 27, and her dog were found dead in a fire at her home on Nov. 13 in La Crosse. A criminal complaint obtained by People says video surveillance footage and cell phone data put Sierra at Pickett’s home during the time of the fire.
An autopsy determined Pickett had been killed before the fire broke out, according to the complaint.
An amended complaint cited by the Milwaukee Journal Sentinel includes 14 additional pages of detail; however, the basis remains the same, the outlet reported.
The original complaint says a friend of Pickett told investigators that Sierra was upset about Pickett’s pregnancy and threatened to take full custody of their 2-year-old son if she refused to get an abortion. On the night of the alleged murders, the 2-year-old was staying with Pickett’s friend.
Sierra reportedly admitted to the affair. Investigators also interviewed Sierra’s wife, who knew about the affair and son Sierra and Pickett shared, but denied knowing Pickett was pregnant again.
Sierra was a mechanical design instructor at Western Technical College at the time of the incident and has since been placed on administrative leave, reported WXOW.
Sierra is being held on a $1 million bond and is expected back in court on Jan. 5, 2026, for a preliminary hearing.
