Showers played a police officer on the cable drama.
His work also includes "The Vampire Diaries," "Traffic," and the coming film, "Colombiana."
A St. Bernard Parish Sheriff's spokesman says the 44-year-old man lived in Chalmette with his girlfriend. He said she reported him missing Tuesday after he didn't return from a night out with a friend in the French Quarter.
The woman told police that Showers suffered from severe depression and was diagnosed in March with multiple sclerosis.