As of 1 p.m., they’d found no sign of him, according to Capt. Paul Starks, a police spokesman.
About 20 people were searching the land around Comsat Drive in Germantown and the area of the Magruder Branch Trail in Damascus, Montgomery County police said.
A K-9 team from the Mid-Atlantic D.O.G.S. Search and Rescue was also assisting in the search.
Monday was the second day of the search. On Sunday, search teams consisting of about 80 people focused on Damascus Recreational Park and Little Bennett Regional Park in Clarksburg.
Police said McQuain has been missing since the weekend of Oct. 1.
McQuain’s mother, Jane McQuain, 51, was found dead Wednesday in her Germantown apartment. Police have arrested Curtis M. Lopez, McQuain’s estranged husband, who is accused of killing her sometime in the past two weeks.
This item has been updated since it was first published.