Arizona Prosecutors Allege Chandler Man Planned Bomb and Gun Attack on Synagogue or Mosque; Defense Says FBI Found Nothing

A 27-year-old Chandler man is charged with a felony count of making a terrorist threat. Maricopa County prosecutors say he planned a mass-casualty attack on a Jewish or Muslim house of worship.

Matthew Bjornholt appeared in a Maricopa County courtroom on Friday, Oct. 16. His attorney says federal agents already looked at the same claims and walked away.

What prosecutors allege

Prosecutor Stephen Garcia told the court that Bjornholt laid out a detailed plan involving firearms, explosives and an accomplice. Under the alleged plan, bombs would go off first. The accomplice would then begin "picking off people" with guns, Garcia said.

Garcia also alleged that Bjornholt kept a copy of "The Anarchist Cookbook" and called it his "Bible." Investigators seized three guns and ammunition from Bjornholt's home.

Garcia asked for a $500,000 cash bond and described Bjornholt as an imminent danger to the community.

The book is a 1969 bomb-making manual by William Powell, who was 19 when he wrote it. Powell later disavowed it and publicly regretted its publication before his death in 2016. The manual has been tied to Oklahoma City bomber Timothy McVeigh, who killed 168 people at the Murrah Federal Building in 1995.

The defense account

Defense attorney Chad Schell says the case is built on unverified hearsay from a disgruntled former acquaintance. Schell described the tipster as a "homeless alcoholic" whom Bjornholt let stay on his couch and then threw out in late September.

"There is no evidence he's a danger to the community," Schell told the court. "What is the evidence that he's a danger to the community? Some hearsay statements from some dude, that my client kicked out of his house two days before September 29."

Schell says the FBI executed a search warrant at Bjornholt's home on Sept. 29. According to Schell, Bjornholt voluntarily gave agents his electronic devices and passwords. Schell says investigators went through the devices, found no evidence of terrorism or bomb-making materials, and declined to pursue federal charges. "And FBI cut him loose," he said.

County prosecutors took over the case more than two weeks after the federal search, according to Schell.

Schell also argued that the three guns were lawfully possessed. He said Bjornholt's civil rights were restored after he completed a sentence on a drug charge. That charge stemmed from a first-degree murder case in which the murder count against Bjornholt was dropped for lack of evidence, according to Schell. He said the ammunition amounted to no more than standard magazine loads.

The FBI has not publicly commented on Schell's description of its search. His account of what agents found and why they stepped back comes from the defense side alone.

Two claims in conflict

The facts in dispute are narrow. Prosecutors say Bjornholt described an attack plan and kept a bomb-making manual. The defense says the plan exists only in the word of a man with a grudge, and that a federal search turned up no corroboration.

Three things are not in dispute. Bjornholt was arrested, he faces a felony terrorist-threat count, and guns and ammunition were taken from his home. Whether those items point to anything beyond lawful ownership is the question the defense has raised.

A terrorist-threat charge turns on what a person said and meant. A tip from a person with a motive to lie is a standard line of attack for defense lawyers. But threats like the one alleged here are also often reported first by people close enough to hear them, and those people are rarely saints. Prosecutors will have to show the court what backs up the account. Bjornholt is presumed innocent.

A different kind of case in Minnesota

The Arizona allegations differ sharply from a terrorism case brought the same week in Minnesota. Federal prosecutors there charged Sheikhdoon Abdullahi Mohamud, 18, of Richfield, with planning a mass shooting at the Mall of America in Bloomington in support of ISIS.

A 23-page FBI affidavit says that investigation began in December 2024. Over 21 months, Mohamud allegedly exchanged messages with an undercover source on social media and encrypted apps. The complaint says he knowingly received a Norinco AK-47 rifle and about 200 rounds of ammunition. Officials said he wanted to kill as many as 60 people.

Minnesota U.S. Attorney Daniel Rosen said agents tried to warn Mohamud's parents about his radicalization in 2025 and were rebuffed. Mohamud's detention hearing is set for today, Oct. 19, according to court records.

What comes next

Bjornholt's case is at an early stage. The court must decide whether the allegations, as presented by the county, justify the $500,000 cash bond Garcia requested.

The larger test is evidentiary. Prosecutors must show more than the account of the man Bjornholt says he evicted, and they must explain what the county sees in the same material the FBI reviewed on Sept. 29 and left alone.