Why have more than a dozen human feet washed up on the shores of the Pacific Northwest?

As of 2014, police do not think a serial killer is responsible for the mystery feet but can’t totally rule out the possibility after the 15th human foot washed up on the shores of the Seattle waterfront this week. Since 2007, an average of two human feet per year have washed up on a 125-mile of shorefront along the Pacific Northwest.

Why have more than a dozen human feet washed up on the shores of the Pacific Northwest?