GAITHERSBURG, Md. — The investigation into the shooting deaths of two Germantown teenagers the night before their high school graduation last week is moving forward. Detectives said Monday that they have interviewed more than 100 people.

“That doesn’t count people calling in,” Capt. Darren Francke, the director of the Montgomery County Police Department’s Major Crimes Division, said on Monday.

Forensics, shell casings, bullets and autopsy results from the “extensive” crime scene still are being analyzed, Francke said.

Dozens of shots were fired when 17-year-old Shadi Adi Najjar and 18-year-old Artem Ziberov were killed while sitting in a car in a Montgomery Village cul-de-sac about 9:45 p.m. on June 5.

Francke says it’s still unclear whether the teens knew their killers.

“This was a very personal act,” Francke said. “That’s not to say that they knew other, again, otherwise I would come here and tell you that it was not random.”

The young men attended Northwest High School, and police hope that classmates sharing information among themselves may lead to helpful tips for investigators.

Francke made a special appeal to anyone who is afraid to come forward. “Come talk to us, because we can offer resources. We can offer help.”

Reiterating how brazen and violent the murders were, Francke said someone with helpful information can “take their chances” by remaining silent.

“Or, they can take their chances and come speak to us. Do the right thing and let us take these people off the street,” Francke implored.

Anyone with information is asked to call 240-773-5070.