SAN DIEGO -- A mental competency examination was ordered Thursday for an 84-year-old man accused of gunning down his estranged wife on a busy street in the Gaslamp District last spring.

Defense attorney Kathleen Lee told Judge Timothy Walsh that her client, Joseph Gotell, was unable to assist her in preparation of his case and asked that he be evaluated by doctors.

Walsh suspended criminal proceedings against Gotell and set a further hearing for March 28.

This marks the second time Gotell has been examined to see if he's mentally competent to stand trial. He was deemed competent in November.

Deputy District Attorney C.J. Mody said at an earlier hearing that Gotell confronted his wife, Deborah, about 2:15 p.m. last May 14 near the corner of Fifth Avenue and Broadway. They argued, and Gotell pulled out a .32-caliber handgun and shot his wife twice in the head and once in the right arm, the prosecutor alleged. She was declared brain dead the next morning.

After the shooting, Gotell threw his gun about 10 feet away and was quickly detained by two security guards, who turned him over to a passing San Diego police officer, Mody said.

The prosecutor said the Gotells had separated after about five years of marriage. The 57-year-old victim was out running errands when she was confronted by her estranged husband, he said.

Authorities have yet to offer an official motive for the crime, but the victim's three adult daughters said their mother had broken away several times from the defendant, but he kept showing up in places where he knew she would be.

Gotell faces 50 years to life in prison if convicted of murder.