Samuel Cassidy, 57, shot and killed nine people and then himself at a Santa Clara Valley Transportation Authority (VTA) railyard Wednesday morning, authorities said.
The FBI told KRON 4 that the home had other explosive devices, which they will detonate Friday.
San Jose police closed off Cassidy’s home following the incident as FBI and ATF agents worked to collect evidence.
Surveillance video showed Cassidy leaving his home Wednesday with a large duffel bag. Video also showed that his house caught fire 3 minutes after he started the shooting.
“What we’re operating under now, and I’m not sure this isn’t going to change, is that he set some kind of device to go off at a certain time probably to coincide with his shooting,” Santa Clara County Sheriff Laurie Smith said during an appearance Thursday morning on NBC’s “Today.”
Cassidy had two semi-automatic handguns and 11 loaded magazines on his person at the time of the shooting, Smith said.
Fox News’ Danielle Wallace contributed to this report.