Mystery surrounds the death of two men who were found dead inside a car in the parking lot of an apartment building at 680 Mix Avenue in Hamden on Tuesday afternoon.

They were apparently shot to death, but it's not clear when the men were shot or whether the shots came from inside or outside the car.

Someone walking in the parking lot around 1:30 p.m. on Tuesday noticed at least one person was in distress inside a car in the Broadmoor Apartments parking lot and called police, Hamden Police Chief Thomas Wydra said.

Firefighters and EMS personnel rushed to the scene, where they found two men unconscious in a blue sedan, then called police.

"Both victims appear to be deceased due to gunshot wounds," Wydra said.

Police then learned that people in the area heard a sound like fireworks or gunshots on Monday night, but police were not alerted until Tuesday.

"My message to the public, at large, is that if you hear something, if you see something, please call us and say something," Wydra said. "We might have been able to commence this investigation much earlier than this afternoon."

When police were at the scene on Tuesday, the car was still running and Wydra said police believe the people found dead in the car were there for a while.

While the men were shot to death, police are not referring to the deaths as a homicide. However, Wydra said, "Whoever's responsible for this act is extremely dangerous."

Police have not said if the incident was targeted or random.

The Office of the Chief Medical Examiner is expected to conduct an autopsy this morning to determine the exact cause and manner of death.

Wydra said police don't believe the incident was a murder-suicide, but thought it could be possible.

Police also believe the two men were killed in the same area they were found and that the bodies weren't dumped there.

The department is going to pour all their considerable resources, including the FBI and New Haven police, into the investigation into the foreseeable future, Wydra said.

No suspect has been identified and police did not have a description of who to look for, but said to report anything suspicious, even if it might only seem like a small detail.

The news was disconcerting to Hamden resident Christine Smaltz.

"“It’s definitely unsettling and to see something like a tragedy like this; and this big, makes you want to lock your doors at night," Smaltz said. "Why didn't anyone see it? Why didn't anyone hear it?"

Police expect to release the names of the two men killed today.