BUFFALO GROVE, Ill. (CBS) — A frantic search continued late Monday for a gunman who ambushed, shot, and killed a couple in a parking garage in north suburban Buffalo Grove.

As CBS 2’s Charlie De Mar reported, police as of 10 p.m. Monday were still looking for the suspect. Authorities earlier in the evening said they had a pretty crisp picture of the suspect, coming from a camera inside the garage where it happened.

The incident took place at 150 Lake Blvd. in a garage for a condo complex for the Cambridge on the Lake complex. When the couple hit the garage remote, they thought they were the only ones entering.

But a man police said is also in his 60s with gray hair and dark clothing slipped in.

As the couple exited their car, police said he came up from behind, engaged in a brief conversation, and then began shooting both of them multiple times — killing them.

The bodies weren’t found for more than three hours after the shooting, when a resident saw the couple unresponsive in the garage.

“I’m very worried about living here,” said resident Barbara Matuzak.

She and her son Stanley are coming and going and worrying.

“Scared that he is still on the loose and they haven’t captured him,” said Stanley Matuzak.

The murders happened late Sunday night. On Monday, police were using advanced sonar technology canvased the small pond behind the condo, looking for any weapon or clue that may help with a case that has a gunman on the loose.

On Monday night, the presence of the Buffalo Grove police still at the scene had some neighbors on edge.

“I was scared when I heard the news because, you know, my in-laws live in the building, and they could’ve been in the garage at that time,” said Tracy Keer.

Keer and her kids came to the Cambridge on the Lake complex to check in on loved ones Monday night.

“They’re older, and we just wanted to make sure they’re OK,” Keer said. “And although they said they’re OK, we wanted to just come and make sure they felt comfortable being here.”

Alex Paver is a retired auto mechanic who worked on the couples cars over the years. He said the community that surrounds the lake is largely made up of Russian immigrants, including the two victims.

“They’re very nice people,” Paver said.

The murders happened late Sunday night. On Monday, police were using advanced sonar technology canvased the small pond behind the condo, looking for any weapon or clue that may help with a case that has a gunman on the loose.

Investigators said they don’t believe the shooter is an active threat to the community. When asked why, investigators said that answer would jeopardize the investigation.

Still, Keer said, “I feel comfort knowing that.”

The names of the couple had yet to be officially released Monday night, as police worked to notify family members. Police have not releasing a possible motive, but have again stressed that this was not a random shooting.