Investigators believe two male teens killed the night before high school graduation were targeted, that multiple shooters were involved, and that someone knows something, but isn't speaking up.

Montgomery County Police Capt. Darren Francke said at a news conference Friday that they believe the shooters and victims knew each other and there are people, perhaps at their high school, who haven't come forward with information.

"You know what makes me more angry is those killers, they are on the loose and they could strike again. They could strike your friend, they could strike your family, they could strike your kids," said Adi Najjar. His son Shadi was one of the two teens killed.

RELATED: Police speak to more than 100 people in murder of Md. teens

Francke described the "very violent scene" officers discovered June 5 while responding to a gunfire report. They found 17-year-old Najjar and 18-year-old Artem Ziberov dead in Najjar's car in a Montgomery Village neighborhood.

Francke said more than 30 shell casings were found and one teen was shot 10 times, the other four times. He said the teens were targeted and multiple firearms and shooters were involved.

Najjar and Ziberov were honor roll students at Northwest High School in Germantown, where they lived about seven miles away from the murder scene. They were set to graduate the following day.

"We are in a lot of pain, and we are never going to heal for years to come," Adi Najjar said.

Adi and Tina Najjar said they want any shred of information that could help bring them closer to justice. They asked to listen to WUSA9's video of the news conference. They did, until they couldn't listen anymore. Then, Adi had to talk.

"My son was set up, my son was set up, take this picture, my son was set up by somebody he knows, and believe me, we are going to find out sooner or later. We will find out, and we know the police will catch those killers," he said.

The grieving father went on, "My life doesn't mean nothing to me anymore. What my goal is, what my focus is of my life, whatever the years I live, just to find the killers."

RELATED: Suspects shot teens multiple times upon approach

Adi agrees with police that someone knows something.

"There's no information that's called small information, any information—little, big—whatever the size of this information, believe me, that could help."

He had this message to anyone who might have information about the murder of his son and his son’s friend.

"If you know something, and you're afraid for your life, those killers, they don't care about you. Remember that, those killers, they don't care about you. You could be next."

A candlelight vigil is scheduled at 7:30 p.m. Friday. Hundreds are expected to come to Northwest High school where the two were just hours away from graduating. If you would like to volunteer or donate, please click here>>

If you have any information regarding this case, please call police at 240-773-8477. The $10,000 reward for information leading to an arrest has been increased to $20,000.