A lawyer for a former Oklahoma reserve sheriff's deputy charged in the death of an unarmed suspect says defense witnesses will be asked about the role of stress on decision-making.

Robert Bates was charged with second-degree manslaughter in the death of Eric Harris after saying he mistook his handgun for a stun gun.

Outside court Wednesday, lawyer Clark Brewster said deputies believed Harris was "very dangerous" ahead of a sting operation last April in which Harris was killed.

The Tulsa World reports (http://bit.ly/1ROYVn9 ) that Brewster told a judge that witnesses would discuss police use-of-force tactics and how psychological stress affects critical decisions. Brewster also said experts would offer opinions on Harris' medical condition and alleged drug use and how they may pertain to his death.

Bates' trial starts April 18.