SAN FRANCISCO (CBS SF) – A San Francisco political activist and public relations professional who was the subject of an FBI manhunt has been charged with a single count of possessing an illegal destructive device after investigators say they found pieces that could have been used to assemble a damaging bomb inside his Russian Hill apartment.

Ryan Kelly Chamberlain II, 42, who was arrested at about 6:30 p.m. Monday near San Francisco’s Crissy Field, made his first federal court appearance Tuesday. Accompanied by a public defender, he was charged with one count of possessing an illegal destructive device. He did not enter a plea. The FBI says authorities discovered materials at his home that could have caused great harm to the public.

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Authorities had served a search warrant at Chamberlain’s home near Polk and Jackson streets in the city’s Nob Hill neighborhood on Saturday and found alleged explosive materials there, FBI Special Agent in Charge David Johnson said at a press conference Tuesday morning.

The FBI affidavit in support of the formal complaint against Chamberlain (PDF) details what investigators say they found in his home. Of note was a messenger bag which bomb detective say contained a jar filled with batteries and a green powder, a model rocket motor, an ‘electric match’ commonly used in improvised explosive devices, an assortment of ball bearings, a circuit board configured for remote use and jar lid with a wire attached. The bag was found sitting next to Chamberlain’s kitchen table. Authorities said it appears he lived alone.

After the search of his apartment, a nationwide manhunt ensued for Chamberlain, who posted what appeared to be a suicide note on social media earlier Monday, detailing his struggles with depression and trouble with family and work.

“This was a very dangerous and desperate person, I think you can tell from Facebook and social media posts attributed to him yesterday,” San Francisco Police Chief Greg Suhr said.

Suhr said officers received a report on Monday evening from a citizen who spotted someone they believed to be Chamberlain.

Officers spotted him near Crissy Field and were able to take him into custody after a brief foot pursuit, Suhr said.

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Johnson from the FBI said “the public came through” with hundreds of tips from the Bay Area and nationwide about Chamberlain’s whereabouts.

He said with Chamberlain’s arrest, “We think any threat to public safety has been mitigated in this case.”

Johnson said the initial investigation began after the FBI was told that Chamberlain “had items of great concern to us, and some of that was corroborated when we searched his residence.��

FBI officials said that the alleged bomb-making materials found in Chamberlain’s apartment Saturday have been sent to the agency’s headquarters in Washington, D.C., for further examination, but they confirmed that, if put together, the materials had the potential to be an improvised explosive device, or IED.

Chamberlain’s friends have already begun an online campaign to pay attorney fees. As of Tuesday morning, the group had raised more than $6,300 which “will be given to Ryan for his legal defense, or, if he uses a public defender, to use as he sees fit as he gets back on his feet.”

According to court documents, Chamberlain could face up to ten years in prison and fines of up to $10,000 if convicted.

Chamberlain has worked in public relations and on many local political campaigns in the past 15 years, including Lt. Gov. Gavin Newsom’s when he ran for mayor in San Francisco.

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