Within moments of Wednesday morning’s mass shooting in San Jose, federal law enforcement rushed to help the Santa Clara Sheriff’s Office and San Jose police to secure the scene and begin putting the pieces together about what happened.
Law enforcement sources tell Senior investigative reporter Stephen Stock it is is a very complex crime scene, which includes not only the main VTA maintenance facility building and yard but also a second building.
The second building called “building B” is located southwest of the main building, as well as a guard shack and construction equipment parked outside.
Federal officials told NBC Bay Area that five different special ATF explosives sniffing dogs worked the scene in and around the VTA maintenance facility.
They added that each dog trained to sniff out a different substance from gunpowder to plastic explosives and other materials.
One of those dogs hit on an object as a possible incendiary device.
That’s when Santa Clara County’s bomb squad sent in a robot to explore the device in the back-parking lot.
"ATF officials will also assist local law enforcement in tracking the bullets using a system called NIBIN. (National Integrated Ballistic Information Network) It's a way to trace bullet casings and firearms much like a human fingerprint,” said Joshua Jackson ATF Assistant Special Agent in Charge.
Jackson added that when one of the dog’s alerted them on a possible explosive device, it slowed the rest of the criminal investigation.
Detectives had to wait until the scene was cleared. They later told NBC Bay Area that the item that was found by the dog was not an explosive device.
Federal law enforcement officials said it is a complex crime scene and it could take days before investigators are finished.
"It is multiple locations," said Craig Fair, FBI Special Agent in Charge. "It's a very sizable crime scene. We are dealing in there with we are looking at how we to go and how we need to process. That is also going to take some time."