Nearly 80 law enforcement officers and volunteers, using horses and cadaver-sniffing dogs, searched two parks in northern Montgomery County for signs of 11-year-old William McQuain on Sunday.

The search through the woodlands came three days after the arrest of Curtis M. Lopez, who is accused of killing William’s mother, Jane McQuain, 51, in her Germantown apartment sometime in the past two weeks. Her body was found Wednesday, and Lopez, who is her estranged husband, was arrested in North Carolina on Thursday after police found McQuain’s car near Charlotte.

That officers were searching for a body in the woods represents an ominous turn in the case of William, who has been missing for about two weeks, absent from school and regular sports practices. Based on information developed during the investigation, police on Sunday searched parts of Damascus Recreational Park and Little Bennett Regional Park for the Germantown boy’s body.

Capt. Paul Starks, a Montgomery police spokesman, said that detectives still hoped to find the boy alive but that “we can’t ignore this recent information.”

Police declined to discuss what that information was or how they received it, saying they did not want to compromise the investigation. The search party included five dog teams and seven teams mounted on horses.

“A lot of this is heavily wooded” area, Starks said. Nearly 80 people had joined in the search as of Sunday afternoon. The search began about 10 a.m. and was called off at 6 p.m.

“Realistically, as we get more information, we have to follow where it takes us,” Starks said outside a command post at the Damascus park. “Every day this investigation has been going on, detectives have learned more, including today.”

Sunday was the first time police had searched for William’s body, Starks said. Police hope that William might have been dropped off at a friend’s or relative’s house and said they had no evidence that he was harmed.

McQuain, who was found in her bedroom Wednesday after a friend called authorities to say he hadn’t been able to reach her, died of stab wounds and blunt-force trauma, police said. Police charged Lopez in connection with her death, and he is due in a North Carolina courtroom Monday afternoon.

Lopez, 45, has a history of violence, according to court records. He was convicted in 1987 of repeatedly stabbing a man and leaving him on a Pennsylvania highway to die. The man survived, and Lopez was convicted of attempted murder and served a lengthy prison sentence.

McQuain testified at that trial. Friends said she never divorced Lopez.

Neighbors and friends said the last contact they had with McQuain and her son was on Oct. 1. William has not attended school or sports practices since that day.

A neighbor told The Washington Post that a man fitting Lopez’s description was seen going into and out of McQuain’s apartment in early October. A longtime friend of McQuain’s said in an interview that he had spoken with McQuain a day before she went missing and that McQuain told him she was afraid of Lopez and was concerned that he might harm her.