The man suspected of bombing the courthouse had many construction materials, investigators said

A 20-year-old man who authorities say set off a bomb in the lobby of a Santa Barbara County courthouse earlier this week was charged with the crime on Friday.

Nathaniel James McGuire was arrested Wednesday after he appeared in a Santa Maria court to face a gun charge and instead allegedly threw a bag into the lobby that exploded, injuring at least five people in the courtroom and damaging the interior of the building, the US Attorney’s Office said in a statement.

He is now expected to appear in federal court in Los Angeles on Friday afternoon to face a charge of malicious damage to a building using explosives.

The explosion left the courthouse filled with smoke as sheriff’s deputies, Santa Maria police and California Highway Patrol officers scrambled to find and arrest McGuire.

Authorities say they were able to catch him as he tried to get into a red Ford Mustang parked outside. When he was taken away, he yelled that the government had taken away his guns and that everyone should fight back and rebel, federal prosecutors said.

McGuire was there to appear on a gun charge stemming from his July 28 arrest when Santa Barbara County sheriff’s deputies found him in possession of an unregistered, loaded handgun, Santa Barbara County Undersheriff Craig Bonner said.

Inside McGuire’s Mustang at the courthouse, deputies found ammunition, a loaded handgun and a box of explosives, a rifle, a shotgun, more ammunition, what was believed to be a bomb and 10 Molotov cocktails, authorities said.

The bomb is suspected to have been protected by the authorities.

When law enforcement searched McGuire’s home, they found papers that appeared to be used to cook explosives, an empty can with nails stuck to the outside, a bag of matches, black powder and explosives, federal prosecutors said.

“At this point, we believe this is a local incident, involving a local resident, with a local complaint,” Bonner said.

A witness told The Times that the explosion filled the courtroom with smoke and the arrested man was seen with bullets coming out of his pockets and clothes when the officers arrested him.

“I could hear the man who allegedly threw the bomb screaming and shouting,” said Shane Mellon, a representative of the company who was supposed to appear in court. “When they caught him and took off his clothes, bullets came out of his pockets. The bullets were spreading everywhere.”

Authorities say McGuire was wearing body armor when he was arrested.

United States Attorney for the Central District of California Martin Estrada called McGuire’s alleged actions “deplorable.”

“Not only did he injure five people and torture many others, but he was carrying weapons that would have allowed him to wreak havoc had he not been restrained,” Estrada’s statement said.

Times staff reporter Salvador Hernandez contributed to this report.