ORANGE, Conn. — Killing one's mother is a crime so rare that criminologists haven't studied it much. But in this Connecticut town's last two homicides, sons were charged with just that — matricide.

Last week former Lehigh University wrestler Timothy Granata, whose attorney says has had psychiatric problems, was charged with killing his mother. A killer in another case was convicted in 1995.

In both cases, victims were said to be moms ultra-dedicated to their children. Both were killed in quiet, low-crime neighborhoods in a town a few miles from New Haven. Both had ties to the Yale School of Medicine.

"With the rarity of this kind of crime, the coincidence has a low probability" of happening twice in the same town, said John DeCarlo, associate professor at John Jay College of Criminal Justice and former Branford police chief.

In the most recent case, Granata, 22, is alleged to have killed his mother, Dr. Claudia Granata, on Thursday in the family home at 130 Wild Rose Drive, using blunt impact and sharp objects to her head, neck, torso and extremities. Claudia Granata was 58 and her son is charged with murder.

In the town's last homicide in 1992, George Young, 27, was charged and later convicted of killing his mother, Shirley Young, in her Bittersweet Road home by bludgeoning her with a metal baseball bat, then throwing his bloody clothes on the laundry pile as if they were going to be washed. A prosecutor noted police found his shoeprint on Shirley Young's bloodied face, an indication he kicked and beat her. She was 56.

DeCarlo said there were about 125 cases of matricide in the United States in 1980 and only 20 in 2008, the last year statistics are available and in keeping with a steady drop in crimes overall. The one statistic that is known: 97 percent of those who kill their mothers are sons, he said. DeCarlo said males commit more killings overall in both the human and animal world, mainly because they have a biological hormonal predisposition to aggression.

"Because of the rarity of this kind of crime, it's almost impossible to have a profile," DeCarlo said. "It's so rare and so driven usually by some kind of flare of the moment."

Claudia Dinan Granata, wife of Dr. Attilio Granata, currently an associate clinical professor at the Yale School of Medicine, was in private practice with Pulmonary Associates of New Haven and was on the medical staff of both Yale New Haven Hospital and St. Raphael Hospital, according to her obituary, which reads, "Claudia's family was the center of her life; she enjoyed knitting, cooking, playing the piano, reading and playing with her beloved dogs."

A legacy page through the funeral home is filled with fond remembrances and condolences to the family. One woman wrote, "She was a wonderful, caring person and she will be missed. May all of you find healing and peace in the days to come. My prayers are with you all."

Timothy Granata wept and nearly collapsed Friday as he was arraigned in Superior Court in Derby, where a judge declined to lower his $2 million bond and agreed to send him to Garner Correctional Center in Newtown, which has a psychiatric component. His attorney, Charles E. Tiernan III, said in court that Granata has psychiatric issues and while he wasn't taking medication at the time of the killing, there is a chance he should have been on medication.

Granata played football in high school and was on the wrestling team at Lehigh University in his freshman year. Granata was not currently enrolled at Lehigh, according to a university spokeswoman.

Granata did not enter a plea in court Friday, but police say he admitted to the killing when they picked him up near the house and there was blood on his clothing. Police were summoned through several 911 calls from the residence, including at least one from the suspect, they said.

There are still many questions to be answered in the Granata case. DeCarlo said that since Granata has already admitted to his mother's killing, the question is whether he'll use an insanity defense.