Manhattan District Attorney Robert M. Morgenthau said his office takes the charges very seriously that an accountant convicted of grand larceny 14 years ago and arraigned on similar charges in April threatened to kill the prosecutor who handled both cases.

Jack Chang from Queens, NY, is accused of sending threatening letters to the home and office of Gilda Mariani, chief of the Manhattan District Attorney's money laundering and crimes unit, according to the Associated Press.

"We're going to convict him and send him away as long as we can," Morgenthau was quoted saying in The New York Times. "We take it very seriously."

Chang pleaded innocent to the charges.

Various media reports said the letter that was hand delivered to Mariani's home contained a white powder that was determined to be corn starch. The letter that went to her office was delivered from inside the building where she works. The letters contain what the Associated Press described as "nearly identical messages threatening her with physical harm and death."

Disturbing excerpts from the letters have been published in several Manhattan papers and a New York Daily News headline declared, "Ex-con may choke on own poison pen."

Chang, 54, who had been free on $250,000 bail from the April indictment, was arrested and jailed without bail on charges of coercion, placing a false bomb or hazardous substance, stalking, and aggravated harassment. If convicted of the coercion charge, he could face seven years in prison.

Chang also has pleaded innocent to the April charges against him in which he is accused of stealing his clients' tax payments for his personal use. As for the 1995 charges, he pled guilty and was sentenced to one to three years in prison for a tax scheme in which he stole $940,000. He was released after one year.