Friday, February 11, 2022 6:07PM PT

SAN FRANCISCO (KGO) -- A guilty plea is bringing some closure to the family of a security officer at the Oakland federal building, gunned down in a drive-by shooting May 2020. The case is giving us a glimpse into the extremist Boogaloo movement.

On Friday, the two sides agreed that the gunman, Steven Carrillo, 33, should serve 41 years in prison, but the judge made it clear she still has to decide if she'll accept that deal.

Carrillo entered San Francisco Federal Court in an orange jail jumpsuit, shackled at the hands and feet, and faced more than a dozen relatives of the man he now admits killing in May 2020 - Pat Underwood, security officer at the Oakland federal building.

After Underwood's sister read a statement to the court calling Carrillo a domestic terrorist, he described how he planned the attack, how he networked on Facebook and found a driver, and how he used a George Floyd protest that night as cover. He opened the side door on this white van and fired 19 shots with a homemade automatic rifle - a ghost gun, killing Underwood and injuring his partner.

Finally, in a loud, clear voice, Carrillo - the former military police sergeant at Travis Air Force base said, "Guilty, your honor." The parties agreed to a 41-year-sentence. The judge says she still has to decide if she'll accept the agreement.