CLAYTON, Mo. – Beau Rothwell took the stand Thursday morning on the third day of his murder trial. He told the jury that he struck his pregnant wife in the head with a mallet and killed her at their St. Louis County home in November 2019.

The prosecution wrapped its case today with testimony from a DNA forensic expert with the St. Louis County crime lab. That expert confirmed bloodstains found in the Rothwells’ basement and on Beau Rothwell’s truck matched the DNA profile of Jennifer Rothwell.

Defense attorney Charles Barberio called two of Beau’s former coworkers to the stand, as well as a person who he played racquetball with. The three acquaintances, all men, testified to Beau’s low-key, even-tempered behavior and attitude. They described Rothwell as level-headed and never saw any outbursts of anger or frustration.

Finally, Beau Rothwell took the stand in his own defense. He recounted his courtship with Jennifer, saying they met at the University of Missouri in spring 2010 in an engineering lab. They moved to the St. Louis area in 2013 and married in September 2015.

Beau testified that he’d always wanted to be a father and said they started trying to conceive in fall 2018. That December, the couple learned Jennifer had endometriosis. They kept trying to conceive into spring 2019 to no avail. By May and June, Beau testified that it started to feel like a chore and devoid of any romantic spark.

Rothwell said he and Jennifer agreed to cut back on their attempts to conceive. It was around this time, May or June 2019, Beau said he began having an affair.

According to Beau, Jennifer told him she was pregnant in September 2019. They talked about putting a nursery in their home and discussed changing their insurance to cover the costs of having a baby.

Beau was asked about the “three options” he laid out in a text exchange with his mistress. Beau said the third option, waiting to see what happened with Jennifer’s pregnancy, was a way to kick the can down the road because he didn’t want to have to make a decision. He claimed he was lying when he told his mistress that he was hoping for a miscarriage.

Rothwell’s voice cracked multiple times during testimony on Thursday. He wept while talking about building Jennifer a pregnancy calendar to measure the growth of her belly.

Beau was asked to describe the day of Jennifer’s death. Beau said he’d been feeling anxiety and guilt over the affair and knew he needed to tell Jennifer. He told the court he was throwing himself at Jennifer’s mercy and confessed to her while the two sat in their kitchen.

Jennifer grew highly agitated, Beau said, and demanded to know the identity of his mistress. When Beau wouldn’t tell her, he claimed Jennifer shoved him and said she was having an affair of her own and that the baby might not be his.

Beau admitted to standing up and going into a “red haze.” He told the court he picked up a nearby mallet that he’d used to hang wall decorations and struck Jennifer in the right side of her head while she was still seated.

Jennifer stumbled from her chair and tried walking to the attached garage. Beau said he followed her and the two got into a brief scuffle at the top of the basement stairs. In Beau’s words, he struck Jennifer with the mallet again, causing her to fall down the stairs and into the basement.

Beau said he tried to shake Jennifer awake but she was unresponsive. He testified he went into a panic mode and set out to clean the house of Jennifer’s blood. He discussed going to a nearby grocery store twice to buy cleaning supplies and gloves, and his decision to load Jennifer’s body into the back of his truck. Beau said he put all of the used cleaning supplies in trash bags and put them in the truck bed with her body. He abandoned her body along Highway 61 in Lincoln County between 2:00 a.m. and 3:00 a.m. on November 12.

Beau said he made the decision to strip Jennifer’s clothes because he “saw it on crime shows.” He then stopped at a business on the way home and tossed the garbage bags in the dumpster. Once back at home, Beau said he kept cleaning throughout the night and drove Jennifer’s car and left it abandoned on the side of Olive near Fee Fee, which is a very busy intersection. He also used Jennifer’s phone to call his phone. Beau said he walked home and then decided to go to work in the morning in order to, in his words, keep up a facade of normalcy.

Beau left work during lunch and returned home to continue cleaning up Jennifer’s blood. He admitted to helping Jennifer’s friends and family search for her over the next day, knowing she would not be found.

Closing arguments in the trial are expected this afternoon. Rothwell faces charges for first-degree murder, tampering with physical evidence, and abandonment of a corpse. The jury can reduce the murder charge to second-degree murder or voluntary manslaughter.