A twisted teen is accused of slaughtering four family members during a shooting spree inside a Utah home, reports said.

Neighbors called cops to the Eastmoor Drive home in Grantsville around 7 p.m. Friday after hearing gunshots, according to the Salt Lake City Deseret News.

Authorities discovered five people with bullet wounds and arrested the suspected teen killer, officials said.

One of the victims was taken to the hospital alive. None have been identified.

Grantsville Mayor Brent Marshall said the killer’s motive is unknown for now.

“I’m sure it will take days or even longer to try and piece together what brought all of this one and why it happened, if we ever get to know why it happened,” Marshall said. “It’s upsetting. This is normally a very quiet neighborhood, and any time you have children involved in something, it becomes very emotional, very fast.”

Gov. Gary Herbert urged gun safety in the wake of the carnage.

“Parents and grandparents, secure your firearms! Everyone, hug your loved ones tight. And remember love, not hate, will heal broken individuals and families,” he tweeted early Saturday.