For most people, a visit from the FBI would be a sobering experience, one that might make them reconsider their actions.
But federal agents say Marc M. Keyser was a very determined man.
So, after two FBI agents paid him a visit Wednesday to ask whether he had mailed 120 hoax anthrax letters around the country, Keyser got busy, authorities say.
In the four hours it took the agents to obtain an arrest warrant and return to his Sacramento apartment, Keyser had retrieved new addresses off the Internet, was assembling packets of a white substance along with CD's of a book he wrote, and was preparing to resume his mass-mailing campaign, according to the FBI.
But he was cooperative, surrendering without resistance.
Authorities say that the suspicious substance so far has proved to be sugar and that the mailings - which went to The Bee, other newspapers nationwide and a Sacramento Starbucks - were an apparent attempt to draw attention to a novel he wrote about a fictional anthrax attack.
The scenario emerged in federal court Thursday as Assistant U.S. Attorney Benjamin Wagner argued to a judge why Keyser is dangerous and should remain behind bars.
"I have strong concerns he is unwilling to conform to provisions of the law," Wagner told U.S. Magistrate Judge Kimberly J. Mueller.
Keyser, who is charged with three counts of mailing the hoax packages, was ordered held without bail pending a further hearing Friday on the detention issue.
In a hallway interview after the hearing, Wagner said Keyser could wind up owing tens of thousands of dollars in restitution for responses by hazardous materials teams and law enforcement officers across the country.
He said an unknown number of the packages are probably yet to be delivered, and the Washington, D.C., headquarters of the FBI has issued a national alert to field offices advising that they may be getting calls from recipients.
"Police and hazmat teams have rolled out all over the country," the prosecutor told Mueller.
Wagner also argued that Keyser is a flight risk, noting he has "no regular employment, no immediate family in this area, no assets with which to post a bond."
However, Assistant Federal Defender Rachelle Barbour asked that the bail question be continued to Friday. She said Keyser's mother and sisters, who live outside California, are trying to arrange collateral for a bond.
Keyser, slightly stooped with a pink, square face topped by thinning white hair, was handcuffed and wearing standard jail-issue orange coveralls.
He spoke only once, saying "Yes" in a soft voice when Mueller asked if he wanted her to appoint the federal defender's office to represent him.
Mueller explained to Keyser the charges, the maximum sentence (five years on each count), and his rights. She also warned him that, under a tough 2004 law stiffening the penalties for crimes like the ones he is charged with, he could be ordered to reimburse all the public agencies that devoted resources to deal with his alleged handiwork.
Keyser has annoyed law enforcement and other groups since the 1990s with his bizarre mailings, including allegations he once sent out vials of excrement.
The 66-year-old self-appointed AIDS and education activist was investigated for a hoax anthrax mailing once before in 2006, when the Sacramento News & Review received a CD copy of his novel and a cylinder marked "anthrax," court documents state.
He chose that weekly newspaper, the documents state, because it had done a story in 2002 "about Keyser's crusade to expose the vulnerability of terrorist attacks on the drinking water system."
At the time, the FBI "explained to Keyser that his actions had disrupted operations at the Sacramento News & Review, had precipitated a full Fire/Hazmat response and law enforcement investigation," an affidavit by FBI special agent Filip Colfescu states.
"Further, he was told that such actions were in violation of federal law ... and warned that any further occurrences would likely result in his prosecution."
Keyser apologized and promised never to do it again, the affidavit states.
FBI agents say he mailed out the latest batch of letters - complete with CD copies of his novel - across the country. At least some of them included his return address, and agents went to his home Wednesday to discuss the case. Court documents state that when they arrived, Keyser admitted he had sent the packages.
He then led the agents to 11 unmailed packages in his vehicle, the documents state.