The husband of a Tishman Speyer executive who has been missing since New Year’s Day went online to look up ways to dismember and dispose of a body, and clothes and other items belonging to the executive with her DNA were found at a trash processing facility, a prosecutor said at his arraignment Wednesday on murder and other charges.

Not guilty pleas were entered on behalf of Brian Walshe, 47, and he was held without bail in Quincy District Court. He did not speak except to tell the judge he understood the charges.

Walshe was already in custody and being held on $500,000 bail after pleading not guilty to misleading investigators searching for Ana Walshe, whose body has not been found.

His attorney, Tracy Miner, did not contest bail but in the past has said her client has cooperated with investigators.

The prosecutor also said in court that someone fitting Brian Walshe’s description was seen on surveillance video disposing of what appeared to be heavy trash bags.

Ana Walshe, 39, was reportedly last seen leaving their home in affluent Cohasset in the early morning hours of Jan. 1, purportedly to take a ride-hailing vehicle to Logan International Airport for a flight to Washington, D.C. where she worked, authorities said. But police have found no indication that she either took a vehicle or boarded any flight out of Logan recently.

She was reported missing Jan. 4 by her employer in Washington, where the couple has a home and to which she often commutes during the week for work at a real estate company, authorities said.

Authorities have searched the family’s home, a wooded area near the home, a trash processing facility in Peabody north of Boston, and a condo complex where Walshe’s mother lives.

The couple’s three young children are in state custody.