Authorities Say Feud Led to Factory Slaying : Crime: Workman arrested in shooting reportedly had been bringing gun to work.

A factory worker who allegedly shot and killed his supervisor during a work break had been prepared to do so for quite some time, carrying a handgun to the San Marcos manufacturing firm for several months, the district attorney’s office said Thursday.

Jose Luis Maldonado, a 22-year-old Oceanside resident and employee of Professional Care Products Inc., apparently had an ongoing dispute with his supervisor that led him to gun down Juan Lopez-Rodriguez during a work break Wednesday morning, authorities said.

“From all indications, it appears that this was not totally unexpected. It appears that he had had this particular idea in mind before this day transpired,” Deputy Dist. Atty. Greg Walden said.

“There seemed to have been an ongoing dispute that basically festered for quite some time, and apparently, for whatever reason, it erupted on that day,” said Walden, adding that the dispute had been over “work performance.”

Witnesses and law enforcement officers said they had no explanation as to why Maldonado chose that time to pull a semiautomatic handgun from his waistband and shoot Lopez in the head.

According to the Sheriff’s Department, employees of the firm, which manufactures orthopedic soft goods, were returning to work at 10:15 a.m. after a break when the shooting occurred. Maldonado then allegedly turned and fired a shot at Adrian Flores, another of his supervisors with whom he reportedly had a disagreement.

Witnesses said Maldonado did not exchange words with anyone immediately before the shooting.

Walden said he did not believe that company executives knew Maldonado had been carrying a gun to work, but he said Maldonado had threatened Lopez before the incident.

Public defender John Jimenez said Maldonado had a rocky relationship with Lopez.

“From what I understand, it’s true that his boss had been provoking him for several months, but I don’t know any more than that. It’s my understanding that there was a tremendous amount of provocation coming from the victim and his friends,” Jimenez said.

Jimenez said that “verbal, physical and mental” provocation took place, but gave no specifics.

Executives at Pro-Care said they knew of no such disagreement, personal or work-related, between Maldonado and Lopez or Flores.

“We have been unable to corroborate anything along those lines. No one was aware of any animosity between” Maldonado and Lopez, company President Greg Stetman said.

Lopez, who had been with the firm for almost two years, had recently been promoted to assistant supervisor. He lived with his wife, Martha, and their 9-year-old twins, a boy and a girl, in Escondido for the past year. Both he and Maldonado worked in packaging at the plant.

Pro-Care, located in the 1700 block of a Costa Meadows Drive, manufactures orthopedic goods such as knee braces, splints and collars.

The shooting came less than a week after a fired employee of General Dynamics in San Diego shot two co-workers in the back of the head, killing one and critically injuring the other.

Maldonado is scheduled to be arraigned today in Vista Municipal Court on charges of first-degree murder and attempted first-degree murder.