SEATTLE -- The FBI is investigating a Seattle man with striking similarities to accused Washington, D.C.-area sniper John Allen Muhammed.

FBI agents found a Bushmaster assault rifle after raiding a Burien storage locker owned by James Wilburn earlier this month.

Wilburn is behind bars as agents try to clear up the mysterious death of his girlfriend, Joleen Abbott, who died last month in Virginia.

Authorities say she and Wilburn had traveled there from Seattle to visit his family.

According to FBI terrorism experts, Wilburn fits the profile of a lone-wolf type of terrorist similar to the D.C. sniper.