One person is dead and three are in critical condition after a gunman opened fire at a Fresno, Calif., processing plant. One of the wounded is the alleged gunman, reports the Fresno Bee. The shooting occurred this morning at Valley Protein, formerly known as Apple Valley Farms, a poultry processing plant.

Police have identified the shooter as Lawrence Jones, 42, of Fresno, a discharged parolee with an extensive criminal history. He shot himself outside the plant and was described as being in grave condition at Community Regional Medical Center.

A 32-year-old man was found dead inside the plant with a gunshot wound to the head. A 32-year-old woman was found outside the plant with a gunshot wound to the lower back, and two more employees were injured in the plant. The two shooting victims inside the plant are in critical condition, and the woman is in serious condition. None of the victims have been identified, pending family notification.

Alleged gunman Lawrence Jones had worked at Apple Valley Farms for 14 months, police said.  According to a co-worker, when Jones came to work this morning "he did not appear to be himself," Fresno Police Chief Jerry Dyer said.  About 3 1/2 hours later, he pulled out a handgun and opened fire, shooting four people, police said.

Authorities don't know what may have provoked the attack.

Sources: Fresno Bee, CNN