A Texas judge on Friday ruled that a man is mentally competent enough to be executed next month for fatally shooting his two young daughters more than 15 years ago while their mother listened helplessly over the phone.

State District Judge Robert Burns made the determination about 61-year-old John David Battaglia after a two-day hearing that concluded earlier this week.

The U.S. Supreme Court has declared that a prisoner can be executed if he or she is aware that the death penalty is set to be carried out and has a rational understanding of why he or she is facing that punishment.

Three psychologists testified that Battaglia, a former accountant, doesn't understand why he is scheduled to die. A fourth said Battaglia is faking his delusions.

Battaglia was due to be executed March 30, but a federal appeals court halted it so that his competency could be reviewed.

Battaglia was convicted of killing his daughters, ages 6 and 9, at his Dallas apartment in May 2001. Authorities said he killed the girls to get back at his ex-wife, who was their mother, for lodging complaints with his parole officer that led to a warrant for his arrest.

His new execution date is tentatively scheduled for Dec. 7.