The former congressional candidate arrested by the FBI on Wednesday was seeking to kill a man who was 6 feet tall and 220 pounds, according to a criminal complaint filed Thursday in U.S. District Court in Madison.

Jeremy J. Ryan, 30, is charged with attempting to possess radioactive material with the intent to cause death or serious bodily injury.

An affidavit filed by an FBI agent assigned to the Milwaukee Field Office’s Joint Terrorism Task Force does not identify Ryan’s target, and it’s not clear if the FBI ever knew who the target was.

The affidavit indicates Ryan went to a website where illegal substances are sold and contacted a seller who was actually an FBI “covert employee” posing as a seller of radioactive substances, according to the criminal complaint.

Ryan told the seller he was looking for a poison that would kill and which couldn’t be detected, “preferably something that is not going to be extremely brutal and drawn out,” according to the complaint.

After a series of messages, some of them encrypted, Ryan was told the price of the item would 0.086218 bitcoin, or $569 on that date, according to the affidavit.

The specific substance Ryan is accused of trying to procure is not identified.

A package containing an inert substitute for the radioactive material was delivered to a UPS store on Odana Road in Madison, where Ryan picked it up, according to the affidavit.

Ryan later was arrested in Black Earth.

At his initial court appearance Thursday, the government asked for Ryan to be held in custody, and the judge agreed, according to online court records.

A probable cause and detention hearing is set for Monday. An arraignment is set for Thursday, Nov. 15.

The maximum penalty for the charge is life in federal prison.

Ryan ran unsuccessfully for the Republican nomination for the 1st Congressional District seat in the August primary and in the primary four years earlier, making the legalization of marijuana a prominent part of his campaign.

The investigation included the efforts of the FBI, U.S. Postal Inspection Service, Dane County Narcotics Task Force, Dane County Sheriff’s Office and Town of Madison Police Department, according to the release.