Houston police searched and cleared the home of a man suspected in last month's killing of former President George H.W. Bush's doctor, after SWAT teams surrounded the house Thursday night, reports said.

Joseph James Pappas, 62, has been charged in the murder of Houston cardiologist Dr. Mark Hausknecht.

A neighbor alerted authorities after seeing an open gate at the house in Houston's Westbury neighborhood and spotting someone who resembled the wanted man, the Houston Chronicle reported, citing a source familiar with the case.

“Nobody remembered that gate being open, and also ... light was seen on inside the residence,” Houston police Chief Matt Slinkard said.

Police searched and cleared the area “in an abundance of caution,” he said. There was no indication the suspect has returned to his residence, the chief said.

Some of the lights in the house are motion-activated, and a moving items such as a fan could set that off, Slinkard said.

It was unclear if the suspect fled the country, so police were focused on locating Pappas locally, he said.

Investigators had said Pappas was believed to be armed and dangerous, according to Houston's Fox 26.

Houston police also previously said they were looking into whether Pappas tried to sell various weapons online several days after the July 20 fatal shooting of Hausknecht.

Police allege Pappas shot Hausknecht while the cardiologist rode his bicycle to work at Houston Methodist Hospital.

SUSPECT IDENTIFIED IN MURDER OF H.W. BUSH'S FORMER DOCTOR

Hausknecht was shot three times while he was on his bike and Acevedo said the shots that Pappas is accused of firing -- as he also rode on a bike -- "took some skill."

Acevedo said Wednesday that Pappas might have been seeking revenge for his mother, who died on the doctor's operating table more than 20 years ago, in April 1997.

The Associated Press contributed to this report.