He should have been starting the next phase of his life as a high school graduate, but instead 17-year-old Shadi Najjar of Germantown was laid to rest on Wednesday.

Najjar and his friend, 18-year-old Artem Zibarov, were shot to death Monday night, the night before the two were set to graduate Northwest High School.

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On Wednesday, people packed the Islamic Center of Germantown for a funeral prayer for Najjar. His father, Adi Najjar, spoke to WUSA9, and had a message for his son's killer.

"I want whoever watches the news, please, if you know anyone who killed my beautiful boy, please, you need to call. The reward is going to be $20,000 now and I'm going to keep increasing it until we find who killed my beautiful boy," he said.

Montgomery County police won't say if the two teens were targeted as they sat in a car in a Montgomery Village cul-de-sac after 10:30 p.m. or if they were killed at random.They also won't say if they have identified any suspects. They also won't say why the teens were in that neighborhood, about 7 miles away from their Germantown homes.

Aid Najjar recalled the last time he saw his son alive.

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"He's a good boy, he kissed me and said I'll see you dad, today is my day, I need to go and have fun. I said fine."

Montgomery County police say they are receiving tips, but they are requesting more. They say no tip is too small. You can call Major Crimes Division at 240-773-5070.

Friends have started a GoFundMe account for the families of Najjar and Zibarov.