Nathaniel James McGuire, 22, of Santa Maria, California, pleaded guilty on Sept. 14, 2026, to detonating a bomb inside the Santa Maria courthouse with the intent to kill Santa Barbara County sheriff’s deputies. The 2024 attack injured three people, caused approximately $35,000 in damage and forced the courthouse to close for several days.
McGuire pleaded guilty to one count of use of a weapon of mass destruction and one count of malicious destruction of a building using an explosive. He is scheduled to be sentenced on March 1, 2027, and faces a maximum penalty of life in prison. He has been in federal custody since September 2024.
According to his plea agreement, McGuire entered the courthouse, which serves the Santa Barbara County Superior Court, on Sept. 24, 2024, and threw a backpack containing an explosive device past the security screening area toward sheriff’s deputies. The bomb slid between a victim’s legs and detonated outside a courtroom. Five people were hospitalized and released the same day, and three victims suffered personal injuries.
After the explosion, McGuire went to his vehicle to retrieve two long guns and 10 Molotov cocktails, intending to return to the courthouse to kill sheriff’s deputies and a judge, according to his admissions in the plea agreement. A courthouse security guard and several law enforcement officers stopped him at the vehicle.
McGuire admitted that he bombed the courthouse in retaliation for alleged government wrongs, including the seizure of his firearms by Santa Barbara County sheriff’s deputies earlier in 2024. He intended to harm the judge and deputies because of their status as government employees and officials. A search of his residence also yielded other materials related to bomb making.
The FBI’s Joint Terrorism Task Force, the Santa Barbara County Sheriff’s Office and the Santa Maria Police Department are investigating the case. Assistant U.S. Attorneys Mark P. Takla and Kathrynne N. Seiden are prosecuting it with assistance from Assistant U.S. Attorney Alexander Su and Trial Attorney Patrick Cashman of the Justice Department’s Counterterrorism Section.