February trial set for affluent Oklahoma volunteer deputy Robert Bates charged with killing suspect Eric Harris
Tulsa County reserve sheriff's deputy Robert Bates appears on NBC's 'Today Show' on April 17, 2015.

A white part-time Tulsa sheriff's deputy who has said he mistakenly fired his handgun instead of his Taser when he killed a black suspect in April pleaded not guilty on Monday to second-degree manslaughter and will stand trial in February.

Robert Bates, 73, a white insurance executive who served as a volunteer deputy with the Tulsa County Sheriff's Office, faces two to four years in prison if convicted of the charges stemming from the fatal shooting of Eric Harris, 44, on April 2.

Bates was trying to help officers subdue Harris, who had fled after allegedly trying to sell a gun illegally to an undercover officer. The incident was captured on video.

The judge set a Feb. 8 trial date for Bates.

The shooting prompted investigations into whether Bates received special treatment due to his donations to the department and his personal ties to Tulsa County Sheriff Stanley Glanz.

The shooting was one in a series that raised questions about police use of force in the United States, especially against minorities.

(Writing by Jon Herskovitz; Editing by Will Dunham)