A suspect has been arrested for last week’s bio-terror scare, which caused Alumni Hall to close for the afternoon May 31.

Marshalltown resident Anand Gundo Nariboli, 46, faces three federal charges with a potential sentence of more than 15 years in prison.

Law Enforcement Coordinator for the U.S. Attorney in the Southern District of Iowa Al Overbaugh said Nariboli, who was arrested at his apartment on June 1 by members of the FBI’s Joint Terrorism Task Force and the U.S. Postal Inspection Service, faces a felony charge of threatening the use of an explosive, which carries 10 years in prison.

He said Nariboli also faces a second felony charge of mailing threatening communications, which carries up to five years, and obstruction of mail, a misdemeanor carrying up to six months.

In addition to the letter sent to Alumni Hall, which was later revealed to contain Comet Cleanser, Nariboli stands accused of several other crimes, according to a U.S. Department of Justice news release.

He is accused of mailing a threatening letter to the Dow Chemical Company of Milwaukee, Wis. last February and mailing a letter containing D-CON rat poison that broke open at the Des Moines Post Office on May 19.

In a motion filed in U.S. District Court for Nariboli’s detention, he was also accused of threatening to blow up an FBI office and making five phone calls to the Iowa State Patrol radio dispatcher mentioning serial killers and bombs.

Nariboli admitted to sending the letters at the time of his arrest, showed investigators containers holding Comet and D-CON and provided them with a list of several additional people whom he had mailed the substances, according to the release. ISU Police Capt. Gene Deisinger said Nariboli is being held in federal custody at the Polk County Jail.

“There’s been nothing else affiliated with Iowa State beyond the one letter that I am aware of,” said Deisinger, who was present during Nariboli’s arrest.

Overbaugh said Nariboli waived a bond hearing scheduled for June 6, remaining in federal custody without bond.

The Federal Public Defender’s Office, which is representing Nariboli, declined to comment, citing a policy of not discussing active cases with the media.

Deisinger said ISU Police remained involved throughout the process, providing the initial response to last week’s incident, consulting with federal agencies and assisting with the arrest in Marshalltown.

Nariboli was not related to the suspicious materials found May 31 at 124 Hyland Ave.