BUFFALO, N.Y.—Four years after Steven Kurtz was indicted for mail and wire fraud for illegally obtaining biological materials for his artwork, the charges against him have been dismissed, reports the Associated Press. U.S. District Judge Richard Arcara has ruled that the indictment was "insufficient on its face."

The University of Buffalo professor became the target of a federal terrorism investigation that has drawn international attention and criticism when, in May 2004, firefighters found bacteria samples in his home after responding to a 911 call. He had called to report that his wife was dead from an apparent heart attack.

Investigators determined Hope Kurtz had died of natural causes and that the bacteria and related equipment were part of the professor's artwork, but he was indicted a month later on the mail and wire fraud charges, which carried a maximum of 20 years in prison.

Also involved in the case was Robert Ferrell, the former chairman of the University of Pittsburgh's human genetics department, who prosecutors said used his university account to illegally obtain potentially harmful organisms for Kurtz from a supply lab that does not serve individuals. Ferrel was fined $500 in February after pleading guilty to a misdemeanor count of mailing an injurious article to Kurtz but was not given a prison sentence. The maximum sentence allowed for his offense is six months in prison and a $5,000 fine.

Kurtz is a founding member of the Critical Art Ensemble, a collective that has used human DNA and other biological matter to create works meant to address political and social issues.