A federal judge, blaming Eddie Jackson for the slaying of an Alexandria police officer in a drug-related incident last year, sentenced him yesterday to 20 years in prison without parole for his role in a crack ring run out of an Old Town housing project.

Jackson, 18, was taken hostage in May 1989 by a District gunman who came to collect a drug debt and later shot Cpl. Charles W. Hill to death. Jackson pleaded guilty earlier this year to playing a leading role in a conspiracy to distribute hundreds of grams of crack out of the Hopkins Court apartments where he lived.

"But for him, {the gunman} would not have been there and taken him hostage and shot the officer," U.S. District Judge Albert V. Bryan Jr. said before issuing the sentence.

Jamie Martin Wise, the gunman who was an escapee from a District halfway house, also wounded Officer Andrew Chelchowski before dying in a hail of police fire. The incident caused an outcry throughout the Washington region and led to tougher laws allowing local jurisdictions to evict public housing tenants if they are suspected of selling drugs from the residence.

Jackson, who owed his District-based crack suppliers $3,700, already is serving a 10-year state prison term for a related drug conviction.

Assistant U.S. Attorney Liam O'Grady argued for a lengthy prison term, saying Jackson had a long history of involvement in the local drug trade and was "the principal operator of this crack house."

The prosecutor also said that though Jackson became a victim in the hostage situation, Jackson himself created the circumstances that led to the bloody incident. "But for what Eddie Jackson did none of the events on May 22 would have happened," O'Grady told the court.

O'Grady said Jackson knew his suppliers were capable of violence and chose to ignore their demands for payment.

Alan H. Yamamoto, Jackson's attorney, countered that his client had attempted to pay back part of the debt the day of the shooting. Yamamoto said the debt was at least partially the fault of Jackson's mother, Charlotte Durham, "who had permitted that house to be used as a crack house and had been smoking that crack." Durham was convicted last year on drug-related charges brought by the state.

Yamamoto asked for leniency because of his client's youth and lack of criminal history. He argued that Jackson was a small-time dealer working under the orders of co-conspirators who brought the drugs to the Washington area from New York.

Brooklyn resident Bruce Murrell, 18, and Armistead Gravette, 28, of Alexandria also have pleaded guilty in the case. Neither has been sentenced yet. Theodore Henderson III, 19, the last of the four co-conspirators indicted in the case, recently was arrested in New York. Henderson, also from Brooklyn, faces 13 criminal charges.