MINEOLA - Joseph Beer was convicted today of killing his four friends in a 2012 crash on the Southern State Parkway, but the victims' families say they're not satisfied with the verdict.

Beer, 18, was found guilty of six charges, including manslaughter, reckless driving and reckless endangerment in the crash. His four friends were killed when Beer veered off the highway, doing 100 mph.

The jury could not reach a verdict on the most serious charges of driving while intoxicated and aggravated vehicular homicide. Prosecutors say Beer tested positive for marijuana two hours after the crash, but the defense brought in experts during the trial who testified there is no way to prove it impaired his ability to drive.

Brian Barr, the stepfather of 17-year-old Peter Kanhai, told the media that justice was not served and said he wanted a conviction on all charges.

"I don't always feel like we'll find closure," says Barr. "Joseph can see his parents, we'll never see Peter."

Nassau County District Attorney Kathleen Rice says she will likely move forward with a retrial on the two charges Beer was not convicted on. Both sides will be back in court July 2 to decide on a new trial and to set a sentencing date for Beer. He faces up to 15 years in prison.