OAKLAND — After asking his mother to drive him to an FBI building so he could confess to his role in the May 29 killing of a Federal Protective Services officer, Millbrae resident Robert Alvin Justus Jr. told authorities that his soon-to-be co-defendant, Steven Carrillo, had briefly held him at gunpoint as they traveled to downtown Oakland in a van full of firearms the night of the shooting.

These details, taken from a transcript of the FBI interview with Justus in June, were revealed in recent court filings as attorneys for both Carrillo and Justus accuse federal prosecutors of trying to rush the decision of whether to seek the death penalty against the pair.

Carrillo, 32, and Justus, 30, are accused of working together to murder Federal Protective Services Officer Dave Patrick Underwood and attempt to kill his partner outside the Ron Dellums Federal Building in Oakland after they met on a Facebook group associated with the extremist, anti-government Boogaloo movement. In charging records, Justus is named as the driver and Carrillo as the shooter.

“I don’t like this, I am not cool with this,” Justus recalled himself telling Carrillo after climbing into Carrillo’s van at the San Leandro BART station, where the two met in person for the first time. He made the remark after watching Carrillo pull back a curtain inside his van and begin loading a magazine, Justus reportedly told the FBI.

In response, Carrillo casually pointed an AR-15 rifle at Justus, his index finger resting on the trigger as he demanded to know if Justus was “a cop or a rat,” Justus told FBI special agent Brett Woolard.

“When (Carrillo) is filling magazines, what are you thinking at that point?” Woolard asked Justus.

“That I am going to f—ing die,” Justus responded.

Authorities have said that despite Justus’ statement — which laid most of the liability for the killing at Carrillo’s feet — Justus had plenty of opportunity to get away that night. They note that he left the van on foot to scout out the security booth where Underwood and his partner were stationed.

As he stared on at the security booth he’d just riddled with bullets, Carrillo seemed “thrilled,” Woolard wrote in the criminal complaint against both defendants.

“Did you see how they f—ing fell?” Carillo allegedly asked Justus.

Federal authorities say the duo came to Oakland specifically to murder law enforcement officers, and sought to take advantage of protests elsewhere in Oakland that night denouncing the George Floyd killing. On Facebook, they discussed targeting “soup bois” — a slang term for federal officers — a day before the shooting.

Despite their mutual interest in the Boogaloo Boys — an internet-based anti-government movement whose followers have been linked to other violent crimes across the country — Justus and Carrillo do not seem to have much in common.

Carrillo — a U.S. Air Force sergeant stationed at Travis Air Force Base and assigned to an anti-terrorism task force — also had a trucking business registered at his address. He joined the Air Force at 19, according to a published report. His wife, also in the Air Force, died of suicide two years ago.

A week after Underwood’s killing, Carrillo was arrested in Ben Lomond after he allegedly ambushed Santa Cruz County deputies, killing Sgt. Damon Gutzwiller and injuring two other officers. During the shootout he was hit in the hip but carjacked a vehicle and escaped, later using his own blood to write the word “Boog” on the car. He was  detained only after a civilian placed Carrillo in a wrestling hold after thwarting another carjacking attempt.

Justus, by contrast, appeared to have remorse in the wake of Underwood’s killing. He asked his mom to accompany him as he traveled to San Francisco to turn himself in, and recounted to the FBI that he felt forced to help Carrillo after entering his van. Justus also claimed he talked Carrillo out of other violent plans, such as shooting down a helicopter, prosecutors allege.

That Justus may have had a wake-up call after committing a capital offense did not surprise Alex Newhouse, a researcher with the Center on Terrorism, Extremism, and Counterterrorism who has spent more than a year researching the Boogaloo Boys. He said the movement started online with memes joking about the impending start of a second American Civil War, a common belief among Boogaloo followers.

“The dangerous part is, probably the vast majority of people are like (Justus), who picked up his gun, went to do something, then realized he didn’t have the stomach for it,” Newhouse said. “But the danger of radicalization is that you only need a very small number of people to cause a lot of mayhem and destruction.”

“If we have however many thousands of people calling themselves Boogaloo and only .001 percent are like Steven Carrillo, that’s still a lot of people dead,” he added.

Carrillo faces simultaneous capital murder cases in federal and state court, charging him with killing both Underwood and Gutzwiller. His attorney, along with Justus’ defense team, have accused prosecutors of rushing their decision of whether to seek the death penalty.

The defense wants more time as they research their clients’ lives and pore through the massive amount of discovery in the case. Prosecutors have handed over “81,737 pages, 4,559 photos, 131 videos, 13 audios, and 8 device extraction folders” of evidence, according to defense filings.

On top of that, there’s a virus-related issue: The pandemic has hindered attorneys’ ability to get to know their clients, Carrillo’s attorney, James Thomson, wrote in a legal filing last week.

“This not only undermines the ability to build trust on legal issues, but visits with counsel and the teams also serve as a starting point for delving into sensitive issues that inform the mitigation investigation,” Thomson wrote.