As a Massachusetts father of three stands trial for his wife’s alleged murder, a man who was having an affair with the woman took the stand on Thursday.

Brian Walshe is accused of murdering and then dismembering his wife, 39-year-old Ana Walshe, around New Year’s Day in 2023. He pleaded guilty last month, ahead of the trial, to misleading police and unlawfully conveying a body, though he denies that he killed his wife and has pleaded not guilty to murder. Ana Walshe’s body has not been found.

During the trial’s opening statements this week, defense attorneys said that Brian Walshe found his wife dead in bed on New Year’s Day and then panicked and lied to police as they investigated her disappearance — but maintained he did not kill her.

On day four of the murder trial in Dedham, Massachusetts, on Thursday, jurors heard testimony from a man Ana Walshe was having an affair with before she went missing — as well as a voicemail Brian Walshe left him on the day she was reported missing.

William Fastow, a real estate broker in Washington, D.C., said he met Ana Walshe while she was looking for a home in the D.C. area for her family, and helped her purchase a townhouse in 2022.

At the time, Brian Walshe and their three children were living in Massachusetts while he was awaiting sentencing in a federal fraud case after pleading guilty to a scheme to sell counterfeit Andy Warhol paintings.

Fastow said he was separated from his wife when he and Ana Walshe started an affair after she moved to D.C. for a job. 

“We quickly became close friends, then confidants and, before long, we started an intimate relationship,” he said.

“We would share conversations about our lives, what we were going through, personal troubles, those sorts of things,” he said.

Fastow said Ana Walshe was “despondent” about being away from her children so much, and that the children were in Massachusetts with their father because “his home confinement was predicated on him being the primary caregiver.”

“Initially, she felt that it was something necessary for her to get through, but as time came on, it became a significant issue for her. It deeply upset her,” he said.

“Ana felt deeply disappointed that she wasn’t in a position to be the mother the children deserved,” he said.

He testified that the federal fraud case was a “big stressor” in Ana Walshe’s marriage and “it felt like it was holding up her life.” He said she and her husband also had a “heated” argument over credit card charges she told him Brian Walshe made for a sports memorabilia business.

He said their relationship was kept hidden from Ana Walshe’s husband, but it was serious and they were planning to take trips abroad together.

“Ana felt it was really important that when Brian was to find out about the relationship, that he would hear it from her, she had expressed great concern, and I think she felt it would be a strike against her integrity if he found out a different way,” Fastow said.

He said they spent Christmas Eve together in 2022, and that she went up to Massachusetts the following day. He said she and Brian Walshe “had an argument” about her not being with her family on Christmas Eve.

“There were some points of contention,” he said.

He said they were supposed to have dinner to discuss their future together on Jan. 4, 2023, after they were both supposed to return to D.C. after visiting their children over the holiday. But they never had that dinner, and he never heard from her after receiving a text message from her on New Year’s Eve wishing him a happy new year.

Ana Walshe’s employer reported her missing on Jan. 4, 2023. That day, Fastow said he got two calls from Brian Walshe, which he pushed to voicemail. 

“I was in an intimate relationship with his wife. I had not heard from her in several days, and frankly, I was concerned that maybe he had found out and was calling to confront me,” he said.

Brian Walshe left a voicemail on the second call, which was played in court.  

“I was just reaching out to basically everybody I could. Ana hasn’t been in touch for a few days. I spoke to work today. She hasn’t been in,” Brian Walshe is heard on the call while asking if Fastow had heard from her recently. 

“I’m sorry to bother you. I’m sure everything’s fine,” he said.

Fastow said he immediately called back at that point and offered to go to the D.C. townhouse to see if Ana Walshe was there. No one was home, he said.

On cross-examination, when asked if Ana Walsh ever told him that her husband was suspicious that she was having an affair, Fastow said no. He said he had no knowledge if there was any plan for her to tell Brian Walshe about the affair when she went home for Christmas.

Prosecutors allege that Brian Walshe killed and dismembered his wife, then disposed of her remains in dumpsters. The internet history on his devices on Jan. 1 included searches such as “best way to dispose of a body,” “how long for someone to be missing to inherit” and “best way to dispose of body parts after a murder,” prosecutors said.

On Christmas Day, there was an internet search for Fastow on Brian Walshe’s phone, prosecutors said.

Defense attorneys said that Walshe didn’t know about the affair and that there was stress in their marriage due to the federal case but that he loved his wife.