Four people, who were all in their 20s, were shot and killed at a southern Pennsylvania car wash early Sunday.
The shooting happened around 3 a.m. ET in the village of Melcroft, according to Pennsylvania State Police. Officers arrived to the scene and found four bodies and two injured people -- including the suspected gunman, identified as Timothy Smith, 28.
Smith isn't expected to survive after a gunshot wound to his head, officials said.
"It is a possibility that the gunshot wound to Smith was self-inflicted, however that determination has not been made at this point," according to the police report.
Smith was wearing a body armor carrier without the ballistic panels inserted. He had several magazines of ammunition and three firearms -- an AR-15 semiautomatic rifle, 9MM handgun and .308 rifle, police said.
Citing the ongoing investigation, officials said at a press conference, that they couldn't comment on the relationship between Smith and the four victims and haven't released a potential motive.
One of the victims, Chelsie Cline had briefly been involved with Smith, but broke things off months ago, her sister Sierra Kolarik told CNN affiliate WPXI.
The victims, William Scott Porterfield, 27, Chelsie Lou Cline, 25, Courtney Sue Snyder, 23, and Seth William Cline, 21, were shot after they arrived to the self-serve car wash in two separate cars.
Porterfield and Chelsie Cline arrived together, got out of the car and walked to the side of the business where they were both killed, police said.
Snyder and Seth Cline arrived in a pick-up truck, and they were both shot inside their vehicle while it was stopped. While shots were being fired into the front of the car, a woman who had been riding in the back seat was able to hide and survived with minor injuries from breaking glass, police said.
"She is cooperating with the investigation," said Sgt. Jeremy Barni of the Pennsylvania State Police. "Obviously it's a traumatic experience for her."