PHOENIX (KSAZ) - Questions surround DPS' second highest ranking officer after investigators say he followed a pursuit suspect in an unmarked car on his day off.
"DPS this is Sandra," said the dispatcher. "I'm working east, I have firebird on the air, and they're telling us all units need to back off, they only wanted unmarked units up there with them."
"I'm in an unmarked unit because I was off today," said Silbert.
"Yeah, and we know that, although marked units are behind you, we have tons of marked units," said the dispatcher.
Through the radio traffic, it appears at least one dispatcher asked him to update them on the suspect's location.
"Can you keep me updated on location's though?" said the dispatcher.
"Yeah I'll stay with it, it's not problem, you got it," said Silbert.
Throughout the radio traffic, you'll hear Lt. Colonel Heston Silbert stay with dispatch.
"We're going to be passing Carefree Highway right now, still going down I-17 carpool lane," said Silbert. "He's not driving bad, traffic is going to dictate that he can't do much unless he starts getting really erratic."
Investigators say 29-year-old Bradley Moore was behind the wheel and the dispatcher told units he had claimed to be suicidal on social media.
Moore's vehicle eventually slowed down after troopers spiked two of his tires.
Lt. Colonel Silbert was close enough to talk about the incident with dispatchers.
"He got him, he got him, he got him, okay, he hit the sticks, he's not on the 42 but he's still rolling so tell the guy at 244 to get ready for it because now he's starting to pick it up," said Silbert. "He had a blow out standby, yeah our guy got him, yeah we have a blow out, yup."
The truck eventually went over a guard rail near Camp Verde and rolled down the canyon.
"The vehicle is now 400 feet rolled down the side of the mountain," said the dispatcher.
Moore died at the scene.
But now controversy is brewing over Silbert's involvement following the suspect. Authorities are looking into whether his actions were "reasonable."
DPS declined to comment on the specifics, but says the Special Investigations Unit will report on the incident within 60 days.
The Critical Investigations Review Board will determine if any employee's actions were unreasonable.