(Reuters) - Prosecutors in Oklahoma have charged a sheriff's reserve deputy with second-degree manslaughter in the fatal shooting of a man this month in Tulsa, prosecutors said on Monday.

The Tulsa County Sheriff said reserve deputy Robert Bates, 73, fatally shot Eric Harris, 44, on April 2. Bates thought he was using a Taser instead of his gun, they said of the incident seen in a video released over the weekend.

(Reporting by Jon Herskovitz in Austin, Texas)