Agawam man guilty of threatening prosecutor, possessing ricin

Michael Crooker, 57, entered his plea in US District Court in Boston to one count of mailing a letter containing a threat to injure an officer or employee of the United States, and one count of possessing the toxin, ricin, without the required registration, US Attorney Carmen M. Ortiz said.

In June 2004, federal agents raided Crooker’s home on Springfield Street after they intercepted what appeared to be a homemade firearm silencer Crooker had attempted to send through the mail, prosecutors said.

After conducting a search of his apartment, agents discovered an apparent weapons lab, with several dangerous chemicals that could be used to make powerful explosives, Ortiz said. Agents also found castor seeds, from which ricin is derived, and abrus seeds, which are the source of the lethal poison abrin, as well as all the materials necessary to extract the poisons from the seeds, Ortiz said.

The raid set off a panic in the community as 50 residents were evacuated from the two-building apartment complex where Crooker lived and police closed off all public access within a 1,000-foot radius of Crooker’s apartment.

The following month, angered by the arrest and the raid on his home, Ortiz said, Crooker sent a threatening letter to the assistant US attorney prosecuting his case. In the letter, Ortiz said, Crooker invoked the name of Oklahoma City bomber Timothy McVeigh, and wrote, “As Martyr McVeigh’s T-shirt says: ‘The Tree of Liberty must be refreshed from time to time by blood of patriots and tyrants.’ ’’

Ortiz said Crooker then challenged the prosecutor, writing “Bring on your [expletive] and I’ll bring on mine.’’ Crooker also wrote that even an incarcerated person could cripple the US postal system by sending toxins through the mail, according to the US attorney.

A lawyer for Crooker, Russell J. Heiple, could not be reached for comment last night.

In August of the same year, Crooker’s father found a buried vial of powdered ricin on his property, which was powerful enough to kill hundreds of people, Ortiz said. Crooker later admitted to family members that the ricin was his, and indicated it had been there for three or four years, the US attorney said.

Crooker is scheduled to be sentenced June 20. If convicted, he faces up to 15 years in prison, and $500,000 in fines. Ortiz said that as part of the plea agreement, the parties involved will recommend that Crooker serve the maximum 15-year sentence.

With a long history of criminal convictions and of suing the government, Crooker has spent many years in state and federal prison for crimes including larceny and weapons offenses. He has been in custody since his 2004 arrest, Ortiz said.

Stewart Bishop can be reached at sbishop@globe.com.