SAN FRANCISCO (CBS SF) — A San Francisco political consultant who is accused of possessing biological and chemical toxins for use as weapons is due to enter a change of plea in federal court Thursday.

Ryan Chamberlain, 44, of San Francisco, was arrested in the city in 2014 following a three-day manhunt after FBI agents allegedly found the
ingredients of a homemade bomb in his Nob Hill apartment. Chamberlain had been scheduled to have jury selection Wednesday and the start of trial on Tuesday in federal court in San Francisco on six felony counts, including possession of toxins and a homemade destructive device.

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But the jury selection was cancelled Wednesday morning after prosecution and defense attorneys told U.S. District Judge Vincent Chhabria they were preparing a plea agreement, according to the minutes of a brief session in Chhabria’s court.

A hearing on the expected change of plea was then scheduled for 1 p.m. on Thursday before Chhabria.

U.S. Attorney’s Office spokesman Abraham Simmons said he could not comment on which charges Chhabria may plead guilty to.

Chamberlain’s lead defense attorney, Assistant Federal Public Defender Elizabeth Falk, could not be reached for comment Wednesday.

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The charges against Chamberlain were revised and expanded several times as the investigation proceeded and authorities tested materials allegedly found in his apartment. He is currently accused of six counts in a third superseding indictment issued by a federal grand jury on Oct. 22.

The charges include possession of an unregistered destructive device, namely, the alleged bomb — and possession of a gun with the serial
number removed.

Chamberlain is also accused of possession of a biological toxin, abrin, for use as a weapon; possession of an amount of abrin not justified by
research or peaceful purposes; possession of another biological toxin, ricin, for use as a weapon; and possession of a chemical weapon, namely sodium cyanide.

In pretrial proceedings, defense attorneys contended there was no proof the alleged bomb components would have worked as a bomb or that Chamberlain intended to use the substances allegedly found in his apartment for harmful purposes.

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