On Thursday afternoon, December 10, 1981, an Oregon Humane Society employee found what looked like a red parka floating in a pond in the 1000 block of NE Columbia Boulevard in Portland. The parka was being worn by a deceased man identified as 42-year-old Mario Rivera, Hispanic. An autopsy determined Rivera had not drowned; his death was caused by blunt-force trauma to the head from being beaten with a blunt object.

People who knew Rivera described him as rowdy, frequently intoxicated, and verbally abusive, suggesting a troubled life but offering no clear suspect. Witnesses later reported seeing a red object similar to Rivera’s parka in the pond as early as Monday, December 7, three days before the body was found. No arrests were ever announced, and the Portland Police Bureau considers the case unsolved.

Did anyone in the Portland area at that time see someone wearing or discarding a red parka near NE Columbia Boulevard in early December 1981?