Authorities Looking for Man Accused of Killing His Grandparents - NBC Right Now/KNDO/KNDU Tri-Cities, Yakima, WA |

RENTON, Wash.-- King County Sheriff deputies are searching for an ex-con they say killed his grandparents.

Michael Boysen, 26, is considered "an extreme danger to the public and police."

Detectives say Boysen killed his 82-year-old grandfather and his 80-year-old grandmother in their Renton home late Friday or early Saturday.

Boysen was recently released from prison after serving a year for burglary.

Police are also searching for the victim's missing red, 2001 Chrysler 300, license plate 046-XXU. Boysen is said to be 5'10'', about 170lbs.

Investigators believe he's trying to buy firearms.