Woman killed at upscale California senior home, 2 nieces also slain before suspect found dead

STOCKTON, Calif. – An 88-year-old woman was fatally shot in an upscale California senior home and her two nieces were slain in an apparent triple murder that ended when the suspected gunman was found dead, police said.

Investigators suspect Colin McGrattan, 45, killed his ex-wife, Jackie Arata, 57; her sister, Kathleen Arata, 64; and the women's aunt, Chizuko Kenishi, before shooting himself Monday at O'Connor Woods Senior Living center in Stockton.

Investigators said they were looking into whether a financial disagreement prompted the violence.

The deaths brought to nine the number of people killed in a 51-hour period in Stockton, an agricultural city in Northern California.

Police investigating Monday's triple murder said they initially found Kathleen Arata shot to death at her home near the University of the Pacific.

A minivan spotted leaving the scene was located minutes later at the senior home, where police found the bodies of Kenishi and McGrattan inside a room. Scot Sinclair, the senior home's executive director said Tuesday that another resident discovered the bodies after she saw Kenishi's door ajar and told staff who then called 911.

"We are looking at the aspect of did (McGrattan) take his own life?" police spokesman Joe Silva said Monday.

Investigators later found Jackie Arata in the back of her ex-husband's minivan.

Grief counselors were on hand at the senior center on Tuesday as residents and staff attempted to come to grips with the killings, Sinclair said. Two security guards were on duty Monday when McGrattan entered the building and went up to Kenishi's second-floor room as he has done before.

"Everyone is shocked," Sinclair said. "Nobody knew that he would've done something like this? There's no understanding how this happened?"

The nine killings occurred during a violent three-day stretch in Stockton, which has now seen 59 homicides so far this year — one more than the 58 in all of 2011.

"I've never seen this many homicides in such a short time span," Silva said.

Also Monday, a 31-year-old man and 23-year-old were shot and killed in south Stockton in a possible gang-related shooting, police said.

The string of killings began Saturday with the brazen lunchtime shooting of a man outside a fast-food restaurant. Two other fatal shootings occurred late Saturday and early Sunday.