© King County Sheriff's Office via KIRO-TVMichael Boysen
Police are searching for a Washington man suspected of double homicide after his elderly grandparents were found dead in their home, CBS affiliate KIRO-TV reports.

King County Sheriff's detectives said 26-year-old Michael Boysen is considered to be "an extreme danger to the public and police" after he allegedly killed his 82-year-old grandfather and 80-year-old grandmother in their Renton home late Friday or early Saturday.

Authorities said Boysen may be seeking to obtain firearms because he was searching for gun shows on the Internet.

The sheriff's office said the victims' bodies were discovered Saturday evening after a woman reported that she found her parents dead in their home, KIRO-TV reports. The cause of the deaths hasn't been released.

He was released from prison Friday after serving a year for burglary, according to the station. He was reportedly addicted to prescription drugs and would steal from those closest to him, which landed him in jail. His prison record goes back to 2006 when he was 19-years-old.

Authorities described Boysen as a white man, 5 feet 10 inches tall and weighing 170 pounds. Police are also searching for the victims' missing red, 2001 Chrysler 300. Anyone who sees the grandson and vehicle is urged to call authorities immediately.