STEWARTSTOWN, Pa. — A district attorney said Pennsylvania state troopers were justified in using deadly force against an armed 79-year-old man who had a history of mental health issues and refused to drop his gun.

York County District Attorney Tom Kearney said Tuesday troopers had reasonable fear of serious injury or death after Robert Becker refused orders to drop his gun and fired at them.

Police said Becker called York County 911 dispatchers in April and told them he had killed Satan and may have killed his neighbor.

Kearney said Becker then walked onto the porch of his Hopewell Township home with a 9mm handgun and told arriving officers that it would end with “suicide by cop.”

Police said the man fired at one trooper and was struck when they returned fire. Becker fired a second shot as troopers approached the porch and was ultimately killed when troopers again returned fire.

PennLive.com reports police searching Becker’s home found several religious and occult books and walls painted with occult symbolism. Kearney said Becker spent time “communing with the dead or other spirits” in his home.

Kearney described Becker as a “clearly disturbed individual, with bizarre and troubled thoughts.”