SANTA MARIA, CA – September 14, 2026 (STL.News) A California man has admitted to bombing a Santa Barbara County courthouse as part of an attack intended to kill sheriff’s deputies and a judge, bringing a federal prosecution closer to an end while a separate California case involving attempted murder and alleged arsons remains pending.
Nathaniel James McGuire, 22, of Santa Maria, pleaded guilty Monday to one count of using a weapon of mass destruction and one count of malicious destruction of a building using an explosive, according to the U.S. Department of Justice.
The guilty plea provides a much clearer picture of the September 2024 attack than was available immediately after the explosion. McGuire has now admitted that the courthouse bombing was not merely an effort to damage government property. He intended to kill law enforcement officers and planned to retrieve firearms and Molotov cocktails from his vehicle before returning to the courthouse to kill additional deputies and a judge.
McGuire’s case also has a significant history preceding the bombing. Approximately two months before the attack, Santa Barbara County sheriff’s deputies arrested him on a firearms violation. That case ultimately brought McGuire back to the same courthouse he would later attack.
Gun Arrest Preceded Courthouse Attack
The events leading to the bombing can be traced back to at least July 28, 2024.
According to the Santa Barbara County Sheriff’s Office, deputies arrested McGuire after discovering him carrying a loaded and concealed revolver that was not registered to him.
The Santa Barbara County District Attorney subsequently charged McGuire on Sept. 17, 2024, in case No. 24CR07224 with possession of an unserialized firearm.
McGuire was released from custody on bail or his own recognizance in connection with that case, according to the subsequent state felony complaint.
He was scheduled to appear at the Santa Maria courthouse for arraignment on the firearm case on Sept. 25, 2024.
Instead, authorities say, he arrived prepared for violence.
The Sheriff’s Office said investigators determined shortly after the bombing that McGuire’s apparent motivation stemmed from his July firearms arrest. McGuire has now admitted in his federal plea agreement that the bombing was retaliation for what he viewed as government wrongdoing, including the seizure of his firearms.
The July arrest therefore became a critical turning point in the events leading to the courthouse attack.
Bomb Exploded Near Courthouse Security
According to federal prosecutors, McGuire entered the Santa Maria courthouse carrying a backpack containing an explosive device.
He threw the backpack past the courthouse security screening area toward Santa Barbara County sheriff’s deputies.
The bomb slid between a victim’s legs before exploding outside a courtroom.
Five people were hospitalized and released that day. Three suffered physical injuries.
McGuire has now admitted that he detonated the bomb with the intent to kill the sheriff’s deputies, according to the Justice Department.
The courthouse sustained approximately $35,000 in damage and remained closed for several days.
McGuire was wearing body armor beneath his jacket when he carried out the attack, according to the Santa Barbara County Sheriff’s Office.
But the explosion was apparently intended to be only the first stage of the attack.
Guns and 10 Molotov Cocktails Waited Outside
Immediately after the explosion, McGuire left the courthouse and headed toward a red vehicle parked outside.
His federal plea agreement establishes what he intended to do next.
McGuire admitted that he planned to retrieve two long guns and 10 Molotov cocktails from the vehicle and return to the courthouse.
His intended targets remained sheriff’s deputies and a judge.
According to the Justice Department, McGuire intended to “splatter” — meaning kill — the judge.
He never got the opportunity.
A courthouse security guard and law enforcement officers intercepted McGuire at his vehicle before he could carry out the second phase of the attack.
The weapons recovered from the vehicle provide additional evidence of how much more destructive the incident could have become.
Federal authorities previously reported finding a shotgun, rifle, ammunition, flare gun, fireworks, another suspected explosive device, and 10 Molotov cocktails in the vehicle.
Law enforcement rendered the additional suspected bomb safe.
Authorities Found Bomb-Making Materials at Home
Investigators subsequently searched McGuire’s residence.
Federal authorities reported finding an empty can with nails glued to its exterior, matches, black powder, used and unused fireworks, and papers that appeared to contain recipes for explosive materials.
The Justice Department confirmed Monday that investigators seized additional materials related to McGuire’s bomb making from his residence.
Earlier federal court records provided still more detail.
McGuire reportedly told investigators after his arrest that he had tested two explosive devices shortly before the courthouse attack. One detonated while another failed.
He also reportedly told investigators that authorities would find a list of grievances and goodbyes to family and friends on a laptop at his residence.
Those details were contained in the earlier federal investigation and court filings. The publicly available records reviewed by STL.News do not disclose the complete contents of the reported grievance document.
Authorities Said McGuire Wanted People to Rebel
McGuire’s statements immediately after the attack also gave investigators evidence about his motivation.
According to the federal criminal complaint, after McGuire was apprehended, he allegedly yelled that the government had taken his guns and that people needed to fight, rise up and rebel.
Witnesses and authorities also reported that he shouted “Liberty or death” during the attack.
Despite those statements and the involvement of the FBI’s Joint Terrorism Task Force, authorities initially characterized the incident as arising from a local grievance, rather than publicly identifying McGuire as a member of an organized terrorist organization.
That distinction remains important.
The severity and political or anti-government character of an attack do not, by themselves, establish membership in a terrorist organization. Authorities said during the original investigation that they had not established such a connection.
The FBI Joint Terrorism Task Force, Santa Barbara County Sheriff’s Office and Santa Maria Police Department investigated the federal case.
California Prosecutors Allege Three Arsons
The federal prosecution is only part of McGuire’s legal problems.
Santa Barbara County District Attorney John T. Savrnoch filed a separate 10-count felony case against McGuire, case No. 24CR80025.
Those charges include two counts of attempted murder, use of an explosive device with intent to murder, use of an explosive device for purposes of terrorizing, use of an explosive causing injury, multiple arson allegations involving an accelerant and a loaded-firearm charge.
California prosecutors also alleged that McGuire committed the offenses while released from custody in the earlier firearm case.
Perhaps most significantly, prosecutors alleged that McGuire committed several arsons around the Santa Maria area in preparation for the courthouse attack.
The Associated Press reported after the state charges were filed that McGuire was accused of three arson fires.
Those state allegations have not been resolved by Monday’s federal guilty plea. They remain allegations unless McGuire admits them or a court proves them.
The distinction is important because McGuire’s federal guilty plea now establishes his responsibility for the courthouse bombing and his admitted intentions surrounding it, but it does not automatically establish his guilt on every charge brought separately by California prosecutors.
State Case Remains Pending
The Santa Barbara County District Attorney previously said the state prosecution would remain pending while federal authorities pursued their case.
McGuire has remained in federal custody since September 2024.
A federal plea agreement signed Sept. 8, 2026, called for McGuire to plead guilty to the first two counts of his federal indictment. Federal prosecutors agreed to recommend a sentence of no more than 30 years, according to reporting by KEYT News Channel 3-12.
That recommendation does not bind the federal judge.
The Justice Department said Monday that McGuire faces a statutory maximum sentence of life in federal prison.
His sentencing is scheduled for March 1, 2027, before U.S. District Judge Jesus G. Bernal.
The federal plea resolves the two counts covered by the agreement but does not dispose of McGuire’s pending Santa Barbara County prosecution.
No Long Earlier Criminal History Found
A review by STL.News of publicly accessible government records and contemporaneous reporting did not uncover evidence establishing an extensive criminal history for McGuire before the July 2024 firearm arrest.
That is an important distinction.
The documented public record does not currently support describing McGuire as someone with a lengthy history of arrests or convictions before the courthouse attack.
Instead, the known chronology shows an alarming escalation over a relatively short period.
McGuire was arrested on a firearm allegation on July 28, 2024. Prosecutors filed a felony firearm case against him in September. While released in connection with that case, authorities say he prepared explosives, and California prosecutors allege that he committed several arsons in preparation for the courthouse attack.
He then went to the courthouse where his firearm case was scheduled to be heard.
There, McGuire has now admitted, he detonated a bomb intending to kill sheriff’s deputies.
He further admitted that after the explosion he intended to retrieve two long guns and 10 Molotov cocktails and return to the building to kill deputies and a judge.
Law enforcement stopped him before he could carry out that portion of his plan.
Attack Could Have Been Far Worse
The facts contained in McGuire’s plea agreement demonstrate how close the Santa Maria courthouse attack came to becoming a substantially larger mass-casualty event.
The explosive device had already detonated.
People had been injured.
McGuire was wearing body armor.
Additional firearms, ammunition, incendiary devices, and another suspected explosive were nearby.
And McGuire has now admitted what he intended to do with them.
“McGuire launched a vicious, terroristic assault on a court of law with the intent to kill law enforcement officers and a judge,” Assistant Attorney General for National Security John A. Eisenberg said in announcing the guilty plea.
First Assistant U.S. Attorney Bill Essayli for the Central District of California said the attack caused physical, structural and emotional harm and could have produced significantly worse consequences.
The intervention of courthouse security and responding law enforcement prevented McGuire from returning to the building with the weapons stored in his vehicle.
Nearly two years after the attack, the question of whether McGuire was responsible for the courthouse bombing has changed from allegation to admission.
His federal punishment has yet to be determined.
And his legal problems are not finished.
Once the federal proceedings conclude, McGuire still faces the separate California prosecution involving attempted murder and other charges, including allegations that he deliberately set fires while preparing for the courthouse attack.
Sources: U.S. Department of Justice; Santa Barbara County Sheriff’s Office; Santa Barbara County District Attorney; federal and California court records; Associated Press; KEYT News Channel 3-12; Los Angeles Times.
Editor’s note: McGuire has pleaded guilty to the federal offenses described above. Separate California charges, including attempted murder and arson allegations, remain pending and should be treated as allegations unless established by a guilty plea or court judgment.
