A man who detonated an explosive device inside a courthouse in Santa Maria, Calif., and injured multiple people on Wednesday morning has been arrested and charged, the authorities said. The man was to appear in court for his arraignment relating to a July arrest for a firearms violation, the authorities said.

The man, who the authorities identified as Nathaniel McGuire, 20, of Santa Maria, entered the courthouse on Wednesday morning and threw a bag at the screening station, causing an explosion and injuring several people. 

Mr. McGuire was wearing body armor under his jacket and did not sustain any physical injuries from the blast, the authorities said.

Santa Barbara County Undersheriff Craig Bonner said that Mr. McGuire was scheduled to be arraigned in court on Wednesday for a July 28, 2024 arrest by the sheriff’s office for carrying a concealed weapon that was not registered to him, Mr. Bonner said. His motivation “appeared to have stemmed” from that arrest, Mr. Bonner said.

“At this point in time, we do believe this to be a local incident committed by a local individual with a local grievance stemming from his arrest,” Mr. Bonner said, adding that the authorities do not believe there are any further safety risks to the community.

At this point in time, we do believe this to be a local incident committed by a local individual with a local grievance stemming from his arrest,” Mr. Bonner said, adding that the authorities do not believe there are any further safety risks to the community.

Mr. McGuire is being held without bail on charges including attempted murder; using an explosive device in attempting to kill someone; and possession of explosive devices.

The sheriff’s office is also working with the Santa Barbara County Fire Department to investigate whether Mr. McGuire is linked to several recent additional arson fires, Mr. Bonner said. He did not elaborate on those fires.

According to Mr. Bonner, the sheriff’s office received a report of an explosion at 8:48 a.m. local time at the Santa Maria Court Complex near the courtroom where arraignments take place and where Mr. McGuire was set to appear on Wednesday