MINNEAPOLIS (AP) - Hennepin County Sheriff Rich Stanek says the gun Raymond Kmetz used to wound two New Hope police officers before other officers killed him was illegally channeled to Kmetz by a straw buyer.

But prosecutors say the suspect was released Friday because they didn't have sufficient evidence to hold him.

The 68-year-old Kmetz had a history of mental illness and threats against New Hope officials. He was killed Monday night at New Hope City Hall after he opened fire.

Kmetz could not legally buy a gun, but Stanek told reporters Friday night that he bought three online and had a Golden Valley man pick them up for him, including the shotgun he used Monday night.

The county attorney's office says the evidence so far is insufficient to support felony charges.