FRESNO, Calif. (AP) — Employees at a California chicken-processing plant returned to work Thursday as new information surfaced about the psychological history of the ex-convict who police say shot four of his co-workers before killing himself.
A Fresno County mental health evaluation in 2004 diagnosed suspect Lawrence Nathaniel Jones with intermittent explosive disorder, drug-induced psychotic disorder, and dependence on multiple substances including amphetamine, marijuana and alcohol.
Intermittent explosive disorder is a condition marked by sudden aggression that appears out of proportion to any external stress, according to the National Institute of Mental Health.
To be diagnosed with it, a person must have had three such aggressive episodes.
Jones was seen many times by jail psychiatric services staff, who described him as mentally unstable, the Fresno Bee reported.
"The majority of the contacts have been crisis-related," wrote psychologist Adrian Della-Porta. "He has a history of acting out around his court dates. He has consistently refused medication offered to him."
On Tuesday, in the middle of his morning shift at Valley Protein, the 42-year-old Jones pulled a gun and shot four co-workers, killing two, authorities said. Two others were wounded.
Police have not released a possible motive for the violence.
Two of the victims had worked at the plant for less than a week. Another had worked there since June.
Jones' boss and co-workers were puzzled about what set off the ex-convict who had been in and out of prison since 1991 for crimes ranging from armed robbery to car theft — a record his managers were aware of, Coyle said.
They said Jones, who had worked at the plant for 14 months, was a nice, respectful man, and a model employee.
Bob Coyle, president and owner of the Valley Protein plant, said Jones always arrived on time and said hello, and "got the job done" — though he mostly kept to himself.
In 1991, Jones was convicted in Alameda County of robbery with the use of a firearm. In 1994, he was sentenced to 13 years in prison for robbery in Fresno County then released on parole in 2001, according to the California Department of Corrections and Rehabilitation.