Sheriff: Rail Yard Shooter Targeted Victims

Santa Clara County Sheriff Laurie Smith reported that a gunman targeted specific victims in a mass shooting at the Valley Transportation Authority. The 57-year-old gunman, unhappy with his job, had previously expressed violent intentions. On the day of the incident, he set his house on fire and proceeded to the rail facility, where he selectively shot individuals. The motive remains unclear, but investigations are ongoing.

What device did the gunman appear to have set to start a fire?

What is the sheriff's perspective on finding the real motive behind the shooting?