SAN JOSE, Calif. — A gunman who killed nine co-workers at a San Jose, California rail yard had stockpiled weapons and more than 22,000 rounds of ammunition at his house, authorities say, before setting it on fire.

AP

In a release from the Santa Clara County sheriff's office, investigators say Samuel James Cassidy coordinated the fire at his home with the violence at the the Santa Clara Valley Transportation Authority around 6:30 a.m. Wednesday.

The home was heavily damaged in the fire.

A specific motive has not been identified for Wednesday's shooting, however, officials say Cassidy was a long-disgruntled employee at the rail yard.

"It is clear that this was a planned event and the suspect was prepared to use his firearms to take as many lives as he possibly could," a release from the sheriff's office reads.

Inside the home, investigators found 12 guns, multiple cans of gasoline, and what they suspect are Molotov cocktails.

The weapons and ammunition found at the home is in addition to the three 9 mm handguns and 32 high-capacity magazines he brought to the rail yard.