Jul 11, 2013 11:16 PM by Associated Press
FLORENCE- The death of a serial killer convicted of murdering six people in a shooting spree that terrorized Phoenix in 2005 and 2006 has been ruled a suicide.
The Pinal County Medical Examiner's Office announced Thursday that Dale Hausner's death last month was caused by "amitriptyline intoxication."
Authorities say amitriptyline is one of a variety of anti-depressant medications.
The 40-year-old Hausner was found unresponsive on June 19 in his one-person cell at the Eyman state prison complex in Florence.
The state Department of Corrections says Hausner was pronounced dead at a hospital about an hour later.
Hausner was given six death sentences and hundreds of years in prison for killing six people and attacking 19 others in a series of random shootings in the Phoenix metropolitan area.