Howard County prosecutors said they will decide today whether to continue the trial of Dimitrious (Jimmy) Prassos, charged in connection with the slaying of his father, a prominent Ellicott City restaurateur, after a judge said he would not admit testimony from the prosecution's major witness.

Circuit Judge J. Thomas Nissel Jr. said yesterday that prosecutors could not use a tape-recorded statement or testimony from detectives detailing accounts given by a key witness implicating Prassos and his codefendant, William H. Ray Jr., in the robbery at the Pirate's Cove Restaurant Aug. 2.

However, Nissel said prosecutors could use the testimony of three other witnesses, a drug counselor and two former prison cellmates of Ray, who said Ray told them about committing a robbery.

Nissel said he would not allow as evidence the statements given to police by Lisa Williams, 20, of Columbia, who police said told them she had driven the getaway car in the robbery. Nissel said Williams was an unreliable witness because she had made conflicting statements to police.

Williams, who recently moved from Baltimore to Columbia, was the state's key witness linking the younger Prassos to the robbery and murder of his father, George Prassos, 59. She has refused to testify at the trial, invoking her constitutional right against self-incrimination.

Nissel's rulings were on prosecution motions to allow hearsay evidence into the trial. Prosecutors said they have no eyewitnesses to link Prassos to the crimes, mostly statements Ray allegedly made to other people about it. Prassos has maintained his innocence in the crimes.

Nissel ruled yesterday that prosecutors can use hearsay testimony from Kathie McMillen, 27, a former alcohol and drug counselor, who testified yesterday that Ray told her the day after the robbery that he and another man named "Jimmy" had committed a robbery in which they stole $5,000 to $7,000. McMillen, who met Ray while he was being treated at a Towson hospital for drug and alcohol addiction, testified yesterday that Ray also told her that "someone had been hurt" in a robbery.

Herman Eiler, Ray's former cellmate at the Maryland House of Corrections in Jessup, testified yesterday that Ray bragged about his role in the robbery, which he said Ray claimed was arranged by the younger Prassos, "but at the same time, he {Ray} said he didn't mean to shoot the man."