The ex-postal worker who authorities say committed the nation's bloodiest shooting at a postal installation in nearly 20 years also has been linked to the killing of a former neighbor.

The body of Beverly Graham, 54, was found in her condominium a day after authorities say Jennifer San Marco opened fire inside the mail sorting center where she once worked. Another woman wounded in the rampage died Wednesday, bringing the death toll to eight, including San Marco.

"The shell casings found match those found at the postal distribution center," Santa Barbara County Sheriff Jim Anderson told reporters.

He said Graham's neighbors told authorities they heard the sound of gunfire between 7:15 p.m. and 8:15 p.m. Monday night. Beginning at 9 p.m., authorities said, San Marco shot six postal employees and committed suicide at the Santa Barbara Processing and Distribution Center.

Five of her victims died shortly after the attack, and the sixth — Charlotte Colton, 44, of Santa Barbara — died Wednesday morning.

In addition to Colton and Graham, the victims were identified as Ze Fairchild, 37, and Maleka Higgins, 28, both of Santa Barbara; Nicola Grant, 42, and Guadalupe Swartz, 52, both of Lompoc; and Dexter Shannon, 57, of Oxnard.

Anderson said it wasn't clear if the killings were racially motivated. The victims at the postal center included several minorities. Graham, who relatives said had argued with San Marco more than two years earlier, was white.

San Marco's reputation for bizarre behavior had resulted in her leaving the Postal Service in June 2003 after six years. She was granted early retirement on a medical disability because of psychological problems, the U.S. Postal Service said.

"She went through all the requisite screenings. There were no prior indications" of problems, said Keith Blackman, a media consultant to the Postal Service.

Before becoming a postal worker, San Marco, 44, worked as a Santa Barbara police dispatcher in the mid-1990s and passed an extensive background check and psychological exam. She left after a few months, not unusual for a stressful job with a high turnover rate, police Lt. Paul McCaffrey told the Santa Barbara News-Press. The job did not include weapons training.

Acquaintances said San Marco, who was white, sometimes talked to herself and spewed racist comments.

Police in New Mexico, where she moved after leaving the Postal Service, said they once received a call that she was naked at a gas station. A deputy clerk in the town of Milan said she once requested a business license to start a publication called "The Racist Press."

Authorities have said San Marco entered the mail plant by driving through a security gate close behind another vehicle, then taking an employee's badge at gunpoint.