The ex-convict who shot a handful of his co-workers execution-style at a California chicken-processing plant, killing two, kept to himself but was a model employee, according to his boss and neighbors. Lawrence Nathaniel Jones, 42, had been in and out of prison since 1991 for crimes ranging from armed robbery to a car theft. A neighbor described him as intimidating, but a co-worker and his boss said he was nice and respectful. As police tried to determine what motivated Jones' attack at the Valley Protein plant in Fresno on Tuesday, those who knew him painted a conflicting portrait of a man who had a history of mostly non-violent crime but appeared, at least outwardly, to have straightened out his life. Armed with a handgun, he moved methodically among his first three victims a few hours into his morning shift, placing the gun against their head or neck and then pulling the trigger, authorities said. He shot a woman who tried to flee, and then put the gun to one more person's head and pulled the trigger, but the gun was out of bullets, according to police. Bob Coyle, president and owner of Valley Protein, said Jones was then confronted by one of the plant's managers. He left the building, reloaded, and shot himself to death. Fresno police officers look over the area where a man killed himself after shooting people in his workplace that killed at least one person and wounded several others at Valley Protein, formally known as Apple Valley Farms Tuesday, Nov. 6, 2012, in Fresno, Calif. Police say a parolee who worked at the Fresno chicken processing plant opened fire at the business on Tuesday, killing one person and wounding three others, before shooting himself. Police Chief Jerry Dyer said they didn't know what prompted the attack by 42-year-old Lawrence Jones midway through his shift at Apple Valley Farms. Other workers told police he did not appear to be himself when he arrived at the plant for work. (AP Photo/Gary Kazanjian) Close At least his first three victims appeared not to know what was going on. Police said the gunshots were drowned out by the machinery and ear protectors used by the workers who dice, slice, grind and cook chicken. Company managers said they and the employees were still puzzling over what went wrong. On Wednesday, the plant remained closed and the company brought in grievance counselors for employees, some of whom walked out wiping away tears and hugging each other. "Nothing seemed out of the ordinary that day, or any day," Coyle said employees told him. There were no arguments that ensued, nothing that led up to it. It's a horrific, random act of violence. Coyle said Jones never showed any signs of trouble, was always respectful and on time. He was recently given a perfect attendance award. He was a good employee. Never missed a day, never late. He would say, 'Hi Bob. ... I'm blessed to be here.' That's how he'd say things," Coyle said. He kept to himself, he was quiet, but he got things done. Michelle Coyle, the company's co-owner and head of human resources, said managers were well aware of Jones' record and prison time. But Jones came highly recommended from a placement agency, she said. "He was top of the list," Michelle Coyle said. We knew he did not have a violent criminal past. We try to give people a second chance at life. Jones, who had worked at the plant for 14 months, had an extensive criminal history dating back to 1991, authorities said. In 1994, he was sentenced to 13 years in prison for robbery, then released on parole in 2001, according to the California Department of Corrections and Rehabilitation. Jones had also served time for robbery and, later, for vehicle theft and other convictions. He was last paroled in June 2011, the department said. "He was reviewed and he had not had any violations and so he was discharged from parole" this past May, said department spokesman Luis Patino. It's common that a condition of being discharged from parole is having a job, he said. "We want to make sure they can reintegrate into society and support themselves," Patino said.