(NewsNation) — Opening statements began Monday in the murder trial of Brian Walshe.

The 50-year-old Cohasset, Massachusetts, man is accused of killing his wife, Ana Walshe, and dismembering her body two years ago.

Before jury selection began two weeks ago, Brian Walshe changed his plea on two of the charges against him.

He pleaded guilty to improper conveyance of a human body and misleading a police investigation, court documents show. He maintained his innocence on the murder charge.

Brian Walshe allegedly searched web on ways to cut up body: Prosecutor

Lead prosecutor Gregory Connor told the jury that Walshe allegedly searched the internet for ways to not only cut up a body, but also whether a person could be charged with murder if there was no body ever found. 

The day after his wife was last seen, Brian Walshe was caught on surveillance video at a home improvement store buying hundreds of dollars’ worth of cleaning supplies.

“He is panicking and doesn’t understand what has happened and what is happening,” said Larry Tipton, Walshe’s attorney. “It didn’t make sense that someone he’d just been with and enjoyed New Year’s Eve and into New Year’s day was suddenly dead.”

“Sudden unexplained death. It is real. It happens in young people and old. It happens in male and female. It happens during the day and the night and it happens,” Tipton added.

Brian and Ana Walshe had stress in marriage: Attorney

Tipton spotlighted that before Ana Walshe’s death, she and Brian did have difficulty in their marriage after Ana got a job in D.C. to support Brian, which included a huge yearly salary ($300,000), twice what she was originally making.

“Brian would take care of the children while Ana worked in DC. There was stress in commuting back and forth between D.C. and Cohasset,” Tipton acknowledged.

Brian and Ana Walshe had discussed the strain the situation was having on Christmas, according to Tipton. He also mentioned Ana was having an affair with William Bascal, whom she met the night of Dec. 29, 2022.

“The evidence will be that Ana Walshe did not tell her closest friends, some who lived in D.C., that she spent Dec. 29 with about her life,” Tipton said. “She hid the affair. William Pascal was unaware—they behaved differently in public to make sure there was no appearance. Ana said she would be devastated if Brian ever learned of the affair.”

Tipton said Ana Walshe revealed to Pascal that she and Brian had no financial issues and that they owned that townhouse in D.C. worth over $1 million. Furthermore, she and Brian had life insurance policies on their sons.

Brian was also sending Ana listings of properties in the D.C. area while searching for future investment properties, Tipton stated.

Police learned of Ana Walshe’s disappearance from co-worker: Prosecutor

Connor said Cohasset police first learned Ana Walshe was missing from a co-worker, Hugh Dunleavy, rather than from her husband, Brian Walshe.

Ana Walshe was reported missing back in January, when it is presumed she was heading to Logan Airport. Investigators said the mother of three had booked a flight to Washington, D.C., where she works, but never made it onto the flight.

Dunleavy received a call from Brian Walshe about how Ana had flown back early on January 1 and how he was now concerned, since he hadn’t heard from her in several days, according to Connor. Connor added that Dunleavy said Brian Walshe was calm during the call and stated that Ana had left their home for a work emergency, telling him she had to return to D.C.

Brian Walshe was facing serious prison time for fraud: Prosecutor

At the time of Ana Walshe’s death, Brian Walshe was facing serious prison time after being found guilty of selling fraudulent paintings to a Los Angeles art dealer, noted Connor.

Brian Walshe had been ordered to pay $400,000.00 in restitution to the dealer, and was not making a living doing anything else.

Brian Walshe has been in custody since he was arrested in connection with his wife’s disappearance.

The trial is expected to last two or three weeks.