A California man has pleaded guilty to federal charges stemming from the 2024 bombing of a Santa Maria courthouse, admitting that he carried out the attack intending to kill law enforcement officers and planned further violence against deputies and a judge.
Nathaniel James McGuire, 22, of Santa Maria, entered guilty pleas to one count of using a weapon of mass destruction and one count of maliciously destroying a building with an explosive.
McGuire has remained in federal custody since September 2024 and is scheduled to be sentenced on March 1, 2027. He faces a maximum sentence of life imprisonment.
Backpack Bomb Thrown Toward Sheriff’s Deputies
According to McGuire’s plea agreement, the attack occurred on September 24, 2024, inside the Santa Maria courthouse, which houses the Santa Barbara County Superior Court.
McGuire entered the building carrying a backpack containing an explosive device. After walking through the courthouse entrance, he threw the backpack beyond the security screening area and in the direction of Santa Barbara County sheriff’s deputies.
The explosive-filled backpack slid between a victim’s legs before detonating outside a courtroom.
Five people were taken to hospital following the explosion and were released later that day. Authorities said three victims suffered injuries directly attributed to the bombing.
McGuire Admits He Intended to Kill Deputies
Federal prosecutors said the explosion was not an accidental or indiscriminate act.
McGuire admitted in his plea agreement that he deliberately detonated the device with the intention of killing sheriff’s deputies working at the courthouse.
Assistant Attorney General for National Security John A. Eisenberg described the bombing as a deliberate attack on the judicial system and said McGuire had intended to kill both law enforcement officers and a judge.
Eisenberg said the consequences could have been substantially worse without the rapid intervention of courthouse security personnel and law enforcement officers.
Guns and Molotov Cocktails Waiting Outside Courthouse
Prosecutors revealed that the bombing was intended to be only the first stage of McGuire’s attack.
After the explosion, McGuire left the courthouse and headed toward his vehicle, where he had two long guns and 10 Molotov cocktails.
According to his admissions, he intended to retrieve the weapons and return to the courthouse.
His plan included killing sheriff’s deputies and what he described as “splattering” — meaning killing — a judge.
He never managed to carry out that part of the attack.
Security Guard and Police Stop Planned Second Attack
A courthouse security guard and several law enforcement officers intercepted McGuire at his vehicle before he could return to the building with the additional weapons.
Their intervention prevented the confrontation from escalating into another potentially deadly phase.
Federal officials have highlighted the response of security and law enforcement as crucial to preventing significantly greater casualties.
First Assistant U.S. Attorney Bill Essayli for the Central District of California said the attack caused physical injuries, structural destruction and emotional harm while carrying the potential for far more serious consequences.
Firearms Seizure Identified as Motive for Retaliation
McGuire also admitted that retaliation against government authorities was a motivation behind the attack.
Earlier in 2024, Santa Barbara County sheriff’s deputies had seized his firearms.
According to his plea agreement, McGuire believed he had suffered various wrongs at the hands of government authorities and bombed the courthouse partly in retaliation for those grievances.
His intended victims were targeted because of their positions as government employees and officials, prosecutors said.
Courthouse Sustains $35,000 in Damage
Beyond the injuries suffered by victims, the explosion caused substantial physical damage to the courthouse.
McGuire admitted maliciously damaging the government building, with repair costs estimated at approximately $35,000.
The damage was serious enough to force the courthouse to close for several days following the attack.
Investigators subsequently searched McGuire’s residence and recovered additional materials connected to bomb making.
Justice Department Calls Attack a ‘Brazen Act of Terror’
Federal prosecutors have characterized the incident as a particularly serious attack because of McGuire’s admitted intention to target members of law enforcement and the judiciary.
Essayli said people who use explosive devices against police officers, judges and other government personnel must face severe consequences.
Eisenberg similarly described McGuire’s actions as a “vicious, terroristic assault” and said his guilty plea means he will now be held accountable for the violence.
Multiple Agencies Continue Investigation
The investigation has involved the FBI’s Joint Terrorism Task Force, the Santa Barbara County Sheriff’s Office and the Santa Maria Police Department.
Assistant U.S. Attorneys Mark P. Takla and Kathrynne N. Seiden of the Central District of California are prosecuting the case.
They have received assistance from Assistant U.S. Attorney Alexander Su and Trial Attorney Patrick Cashman of the Counterterrorism Section within the Justice Department’s National Security Division.
McGuire Faces Possible Life Sentence in 2027
McGuire will remain in federal custody as he awaits sentencing next year.
His guilty pleas formally establish his responsibility for detonating the courthouse bomb as well as intentionally damaging the building with an explosive.
When he appears for sentencing on March 1, 2027, the 22-year-old could receive a sentence of up to life in federal prison for an attack prosecutors say was designed to escalate from a courthouse bombing into the deliberate killing of deputies and a judge.
