Updated Dec. 1: Revised to include new details from police news conference.

Crowley police said Thursday that a 17-year-old adopted from Russia killed his parents before a standoff with police that lasted from Tuesday night to Wednesday morning.

Carl Edward Brewer

An anonymous caller told authorities Tuesday that 17-year-old Carl Edward Brewer was smoking marijuana and admitted killing his parents, Crowley police Chief Luis Soler said at a news conference.

Police went the home in the 800 block of Buffalo Court, near Wildlife Lane, that afternoon for a welfare check, but nothing seemed amiss.

Officers who returned to the home Tuesday evening detected a "faint odor of death" coming from the house and found the bodies of Troy Gene Brewer, 60, and Mary Sheldon Brewer, 64, inside. According to a search-warrant affidavit, Troy Brewer's body was in a bedroom and Mary Brewer's body was in a bag in the next room.

"As we finished up clearing that room, we heard what we believed to be footsteps coming from the second floor above us," police Lt. Robert Gray said. "I made the determination to back everyone out and contact a SWAT team."

Authorities initially told residents to stay indoors during what they called a "tactical situation."

A neighbor told KXAS-TV (NBC5) that police later evacuated residents to a community center.

Police said at a news conference Thursday morning that authorities tried to negotiate with Carl Brewer for nearly hours but eventually resorted to using tear gas to get him to leave the house and surrender.

Brewer has been charged with two counts of murder. He is being held at the Crowley jail, with bail set at $200,000.

Police said they did not have an exact motive for the slayings, and they did not say how Troy and Mary Brewer were killed. Mary Brewer had reported two handguns missing in the past few days, according to a search-warrant affidavit.

"From our conversations with the suspect, it appears this is unfortunately a tragic event that started as a family disturbance," Soler said.

Mary Brewer (via Facebook)

Carl Brewer was the youngest of three children Troy and Mary Brewer had adopted from Russia.

Police said they had been called to the Brewer home 16 times in recent years for incidents that included burglaries and arguments. Carl Brewer was charged with evading officers earlier this year after a police chase.

Pastor C.B. Glidden told WFAA-TV (Channel 8) that Brewer attended Nazarene Christian Academy from 2012 to 2014 and that he and a brother were kicked out of the school over behavioral problems.

"They did have outbursts from time to time from what the boys experienced before adoption in Russia," Glidden said. "That seemed to really impact the choices they made here. This just wasn't the right place for them."

Troy Brewer was a pilot for American Airlines. In a statement, the Fort Worth-based airline said: "We are deeply saddened by the death of Troy Brewer … and we are focused on caring for his family and colleagues during this difficult time."

Staff writer Claire Cardona contributed to this report.