Suspicious device found at San Jose home of VTA gunman rendered safe, investigators say

Two days after Sam Cassidy walked into his workplace at the VTA light rail yard in San Jose and killed nine workers before turning the gun on himself, investigators and detectives remained at his home, where he also set a fire at the same time as the massacre.

On Friday, investigators, crime specialists and a bomb squad team were out in force at Cassidy's home on Angmar Court where they located a "small amount of explosive devices." San Jose police said the devices were rendered safe not long after the discovery. The items included batteries and wiring and were located inside the attic of the home, police said Friday afternoon.

The county sheriff's office also uncovered 25,000 rounds of ammunition at the home and 17 Molotov cocktails at his home.

Some of Cassidy's belongings were still in the front yard Friday morning. Police said Friday afternoon that Cassidy's home was cluttered with items, and that he was a hoarder. When asked if the items were trash or if they had financial value, police said they weren't able to release that information.

Police say that the quantity of contents inside of the home significantly slowed down investigators throughout the investigation.

KTVU cameras spotted a gasoline canister being taken away Friday morning.

RELATED: Here's what we know about the VTA gunman 

Meanwhile, not too far away at the VTA light rail yard on Younger Avenue, agents from the FBI and ATF were helping set up 3D mapping to give a more "wholesome picture" of the crime scene, explained FBI Special Agent in Charge Craig Fair. 

"It helps us better understand the sequence of events, when the shooter entered, how he entered, his movement throughout the facilities," Fair said. 

Investigators have determined that Cassidy was a disgruntled employee, angry with his bosses and co-workers at the VTA. 

SEE ALSO: Could California's red flag law have prevented VTA shooter from owning guns?

Federal agents also revealed a run-in with border patrol in 2016 on a trip back home from the Philippines.

Agents questioned Cassidy on books he had referencing terrorism and his hatred for his job at the VTA. 

However, they determined in a memo his notes did not rise to the level of threat to life. 

That's the reason why local law enforcement did not know about this part of his history until this week. 

Cassidy was found with three semi-automatic guns. Authorities said he shot from all three with dozens of rounds during the rampage.

The Santa Clara County Sheriff's Office is continuing its investigation into the massacre, while the San Jose police department investigates the house fire.