WASHINGTON -- A Republican senator Wednesday questioned the Justice Department's actions against Dr. Steven Hatfill, who is categorized by the government as "a person of interest" in the investigation into the anthrax attacks.

Sen. Charles Grassley, R-Iowa, asked Attorney General John Ashcroft to explain the government policy that prompted the Louisiana State University Academy of Counter-Terrorist Education to sever its ties to Hatfill.

The scientist was placed on administrative leave the day after the Justice Department's Office for Domestic Preparedness e-mailed instructions to "immediately cease and desist" from using Hatfill on any DOJ contract. LSU fired him Sept. 3, saying it had to fulfill its obligations to funding agencies and maintain its academic integrity. The university said it was not making any judgment as to Hatfill's guilt or innocence regarding the FBI probe of the anthrax attacks.

Questions for Ashcroft

Grassley also asked the attorney general to explain the policy by which he publicly identified Hatfill as "a person of interest" in the criminal investigation of the anthrax attacks.

"It is important that the government act according to laws, rules, policies and procedures, rather than making arbitrary decisions," wrote Grassley, the ranking Republican on the Senate Judiciary subcommittee on crime and drugs. The Justice Department declined comment on Grassley's letter, citing the ongoing investigation.

Hatfill denies any involvement in the attacks and says the Justice Department is ruining his life by linking him to the crimes. The FBI says Hatfill is among some 30 scientists and researchers with the expertise and opportunity to conduct the attacks.

Hatfill's lawyer, Victor Glasberg, said he is pleased that "a senator has stepped up to the plate" on Hatfill's behalf.

The scientist has filed a complaint with the Justice Department's Office of Professional Responsibility, saying departmental policies were violated regarding the designation of Hatfill as "a person of interest" and the loss of his job.