Jennifer Sanmarco was regarded as a disturbed and erratic woman at the Goleta mail processing plant where she once worked -- and where she returned Monday night, killing five people before turning the gun on herself in what's being called the worst workplace killing by a woman in U.S. history.Ms. Sanmarco, a petite 44-year-old, 5 feet 2 with cropped brown hair and brown eyes, worked at the Storke Road facility for six years until 2003, when sheriff's deputies took her away in restraints and she never returned as an employee.Jeff Tabala, who retired from the Goleta plant a year ago, knew Ms. Sanmarco and her victims. Standing outside the facility Tuesday afternoon, he and another worker, Rudy Gomez, said they saw Ms. Sanmarco's behavior grow stranger during her time there after an apparent breakup with a co-worker."She was carrying on animated conversations when she was the only one around," Mr. Tabala said. "She sometimes used profanity. She seemed to hear voices. It was enough for me to take my concerns to the shift supervisor. I told him I thought she was unstable. To their credit, a week later, she was gone."

Former co-workers recalling her departure described Ms. Sanmarco as having "flipped out" that day."She wasn't threatening anyone, she was just acting very strangely," said Leslie Blake-Lobb. "For her own safety, they wanted her to leave, to go home for the night.""They got her in a corner, put her in restraints and took her out on a gurney, and she never came back," another woman reported.U.S. Postal Service inspector Randy DeGasperin said she was subsequently put on medical disability for psychological reasons.

Ms. Sanmarco left her Santa Barbara home for western New Mexico, where she again drew attention for unusual behavior. In July 2004, she applied for a business license to start a publication called The Racist Press, said Terri Gallegos, deputy clerk for the city of Milan, told The Associated Press.She engaged in constant conversation with herself during the meeting -- ''not just mumbling to herself, but real audible, like she was arguing with someone but there was no one there,'' Ms. Gallegos recalled.Officials filed a complaint with authorities last spring claiming Ms. Sanmarco harassed a worker during another visit to the office.''

We weren't sure what she was going to do next,'' Ms. Gallegos said. ''She never got violent with us, but she was pretty rude sometimes. At other times she was perfectly fine with us and was normal.''Police in nearby Grants talked to her last June after someone at a gas station called to complain of nudity, Police Chief Marty Vigil said. Ms. Sanmarco was dressed when officers arrived, he said."

We basically told her not to be doing that and sent her on her way.''A phone number thought to be hers in Milan rang unanswered Tuesday, and a dispatcher at the Milan Police Department said she was "told to refer all questions back to the Santa Barbara County sheriff."Mr. Tabala said when Ms. Sanmarco worked at the plant, she was close with employee Kevin Whittemore, who died on Jan. 21. Many employees attended a memorial service in his honor over the weekend. Mr. Tabala wasn't sure what effect, if any, Mr. Whittemore's death might have had on the woman.

Friendship only carried so much weight. A woman who described herself as the best friend of victim Guadalupe "Lupe" Swartz said Ms. Swartz was among the few at the plant who befriended Ms. Sanmarco."They talked when they were at work," she said. "They were friends when (Ms. Sanmarco) was there. I think Lupe even had her phone number and they talked a few times outside of work. But I don't know if she talked to her over the years (since she left the job).""I don't know what brought her back," Mr. Tabala said. "It'd be hard to state any motivation she might have had. I think she seemed like a very troubled person."

James Alan Fox, a criminologist at Northeastern University and an expert on homicides, told The Associated Press that he believed the death toll might be the highest ever for any workplace shooting carried out by a woman.

All of Ms. Sanmarco's victims, save one, were female, and each had been shot in the head.

Most workplace mass murderers are men. Women committed only four out of 53 workplace shootings since 1976 that involved more than one victim, Mr. Fox said.''Men, more than women, tend to view their self-worth by what they do'' at work, Mr. Fox said.Men also appear more prone to use violence in seeking revenge while ''women tend to view murder as a last resort,'' he said.Despite that, some had an inkling of what she was capable of.Jeff Haynes, a 20-year U.S. Postal Service worker, was inside the building at the time of the shootings."The first thing I thought of was her," he said.Mr. Haynes doesn't recall Ms. Sanmarco ever making any threats but described her as "weird.""One day she would be fine and the next day she'd say off-the-wall things," he said.Postal employees who assembled outside the emergency room at Santa Barbara Cottage Hospital early Tuesday morning recalled Ms. Sanmarco's odd conduct, such as "banging on the restroom doors and singing loudly to herself.""Sometimes she'd come in and her makeup would be all, you know, like a clown," said a woman who did not wish to be identified."Maybe she heard voices. Who knows?" the woman said. "When she was taking her meds, she was a nice person."Co-workers said that when she worked at the plant, Ms. Sanmarco was on the 9 p.m. shift -- the same shift during which the shooting occurred Monday night."She knew when to come in that gate," one said.

This story includes reports from The Associated Press and News-Press staff writers Morgan Green, Hildy Medina and Scott Steepleton. E-mail Shelly Leachman at sleachman@newspress.com; Camilla Cohee at ccohee@newspress.com.

All Santa Barbara and Goleta post offices will shut their walk-up service windows today at noon so employees can attend the funeral of Ze Fairchild, one of six postal workers killed in Monday's shooting rampage at the mail processing plant.The service windows at main and branch offices opened later than usual Friday so the workers could attend the morning funeral of Charlotte Colton, also a shooting victim. Richard Maher, a U.S. Postal Service spokesman, said similar closures may occur during funerals in coming days for the rest who died in the tragedy.They are Dexter Shannon, 58, of Oxnard; Mareka Higgins, 28, of Santa Barbara; and Nicola Grant, 42, and Guadalupe Swartz, 32, both Lompoc residents.A seventh victim, Beverly Graham, 54, was a former neighbor of the mass murderer, Jennifer Sanmarco."If employees want to attend the funerals, we are letting them," Mr. Maher said. Postal officials are awaiting word on when the remaining ceremonies will take place. "We are not pressing the families."

At mid-afternoon on Friday, 22 people waited in line for window service at the downtown post office. Those who get mail at home said they had no complaints and had received mail Thursday. One customer commented, "I wouldn't care if it was slow."Postal officials said mail was delivered on all local routes on Friday, although many people might have thought otherwise. Only first-class mail was delivered -- not the advertising "mailers."Since the Goleta plant has returned to 24-hour operation, Mr. Maher predicted that mail delivery for the Santa Barbara and Goleta areas will be back to normal today, including delivery of first-class mail and advertising.Local residents should not expect delays in the delivery of their first-of-the-month government checks, such as Social Security payments, he said.

When the plant was re-opened late Wednesday, one of the first actions by postal officials was finding all government mail containing checks and sending them to Oxnard for processing and delivery, Mr. Maher said. "We knew it was that time of the month, and we know how much some people in this community depend on those checks."Oxnard beefed up its workforce with temporary postal employees from lists of part-timers who worked the holiday season. No Santa Barbara area employees were tapped, Mr. Maher said. The Oxnard plant will continue to be used to ease the load in Goleta as necessary, he said.All shifts at the Goleta plant were asked to return Thursday. Most of the 320 or so workers showed up, although officials said anybody who wanted more time off to recover and get counseling will be accommodated."A lot of them came in and realized the community is depending on them," Mr. Maher said. "They know this has affected the community, too, and want to get back to a sense of normalcy."Although the plant's bulk-mail drop opened Friday at noon, some customers couldn't wait.

On Thursday, mailboxes were stuffed to overflowing outside the Storke Road plant. It was the same at the Goleta Post Office on Patterson Avenue, where mail reportedly also was piled in an open container by the drop box and some pieces were strewn in the gutter.As soon as officials were notified of the problem, the boxes were emptied, Mr. Maher said. "It was an unusual situation. No mail was lost that we know of. The customers should have gone inside the post office. There was staff there all day."