SAN FRANCISCO (KGO) -- A man from Sweden is giving us new insight into Steven Carrillo, the Santa Cruz County Air Force sergeant now held in the shooting deaths of a sheriff's deputy and a federal security officer.
"Someone doesn't just randomly go and kill cops like this," said Daniel Karlsson. "You have to, like, something flips in your brain if you do this."
This young man told us about his many conversations with Steven Carrillo, including right after the first of two shootings. He believes the pandemic and the Black Lives Matter protests played a role in what happened.
RELATED: Steven Carrillo pleads not guilty to murder of Oakland federal Ofc. Pat Underwood
The 22-year-old HR specialist from Malmo, Sweden met Steven Carrillo online because of their mutual interest in physical fitness.
Karlsson told the I-Team's Dan Noyes, "We spoke on Messenger like every other day or every day for like two-and-a-half years and before that on Snapchat, we snapped every day."
Karlsson says he respected Carrillo, a military police sergeant based at Travis Air Force Base in Fairfield, and that Carrillo was always positive and encouraging. He shared some of their Snapchat messages. Carrillo with the user-name "Eternal Physique" wrote, "Bro, it's all about innovation! Always! The thing is we gotta just keep striving, bro."
But, Karlsson tells us Carrillo began to change two years ago with his wife's suicide; the couple had two young children. Then came the coronavirus pandemic.
RELATED: Steven Carrillo charged in Oakland, Santa Cruz Co. officer killings linked to Boogaloo movement, federal investigators say
Noyes: "Did you actually talk to him about the quarantine and the pressures that it was giving him?"
Karlsson: "Yeah, Yeah, I did. The world had changed for everyone. Like nothing was what it seemed to be. Nothing works, what it was like before. And like that uncertainty, probably bred like some unhealthy thoughts in his head."
As protests against police brutality raged across the country, Carrillo, the military police officer, began voicing his own concerns on Facebook.
One post said, "Who needs Antifa to start riots when you have the police to do it for you..."
Karlsson added, "During the quarantine, he like really hated the police. Like this was, this was going on. He just switched it during quarantine."
RELATED: Federal officer shooting suspects Steven Carrillo, Robert Justus 'came to Oakland to kill cops,' FBI says
The federal indictment against Carrillo includes his Facebook posts from the morning of May 29th. He used the jargon of the Boogaloo movement, extremists who believe that civil war is coming. With protests scheduled for Oakland that night, Carrillo wrote, "It's on our coast now ... It's a great opportunity to target the specialty soup bois," meaning the alphabet soup of various law enforcement agencies. Robert Justus of San Mateo answered, "Lets boogie."
Noyes: "Did he talk at all about his plans?"
Karlsson: "He never mentioned anything. He never did."
That night, the indictment says, Robert Justus drove Carrillo's white van past the guard post at the Oakland Federal Building; that Carrillo slid the side door open and fired a machine gun, killing security officer Pat Underwood and badly injuring his partner.
Justus later told investigators Carrillo was "excited and thrilled after the shooting" and that he said, "Did you see how they ___ fell."
Daniel Karlsson tells us he spoke with Carrillo the next morning, but that he didn't mention the shooting. "He seemed like agitated like, breathing like (huffs) ... 1558 He was very short like he wanted to get off the phone."
Karlsson says he lost contact with Carrillo, didn't hear a word, until eight days later. A witness spotted the same white van parked in Ben Lomond with weapons and explosives inside. When deputies went to Carrillo's house, the indictment says he opened fire with the same machine gun and tossed explosives, killing deputy Damon Gutzwiller.
Carrillo briefly escaped in a carjacking, but neighbors were able to tackle him and hold him for police. As they led him away, Carrillo may have revealed his motivation for the shootings.
Steven Carrillo shouted, "This is what I came here to fight, I'm sick of these goddamn police."
I-TEAM: Air Force sergeant arrested on suspicion for killing of deputy in Santa Cruz County
Investigators found a tactical vest Carrillo had with a Boogaloo patch, and before his arrest, the indictment says he scrawled Boogaloo sayings on a car with his own blood, including "boog", "stop the duopoly" and "I became unreasonable."
"Nah, this is, this doesn't sound like the Steven I know."
Daniel Karlsson tells the I-Team he has already tried to reach Carrillo's defense team, to urge them to pursue an insanity defense.
"This wasn't Steven, you could tell this wasn't the guy like, it's as if like some, like someone else just took over his brain, that's the impression I got, just flipped overnight, just became a different person."
This could be a death penalty case. Carrillo has another court appearance in three weeks.
For a look at more stories and videos by the ABC7 News I-Team go here.
What pushed accused cop killer Steven Carrillo over the edge? Former friend weighs in
More TOP STORIES News