An Alexandria judge agreed yesterday to appoint a special grand jury to probe allegations of misconduct by city officials in connection with a drug investigation after the city prosecutor said he could not properly conduct the inquiry.

The action by Chief Circuit Court Judge Donald H. Kent came as the former police investigator who headed the drug inquiry released an internal police memo stating that the investigation's focus had been two-pronged: to look into "major narcotics distribution" and "the possible involvement and/or usage of narcotics by Alexandria Sheriff Michael E. Norris."

The investigator, Charles Cox, has alleged along with two other police officers that Public Safety Director Charles T. Strobel prematurely halted the drug investigation before the accuracy of allegations could be established.

Cox's memo lists several reputed associates of Norris, several of whom were described as close friends, who Cox said were involved in drugs.

Norris has repeatedly denied any criminal wrongdoing and called the allegations against him part of a politically motivated "witch hunt." Repeated efforts to reach Norris last night were unsuccessful.

Cox said yesterday he wrote the memo April 20, shortly after he was told by his superior, Lt. Arthur Bratcher, commander of the Special Investigation Division, that the drug investigation had been terminated. Bratcher did not return a reporter's phone calls.

In his memo, Cox wrote that "as far as Sheriff Norris, the investigation thus far hasn't proven any criminal violations but it's the opinion of this investigator that he is -- to some extent -- involved in the usage of narcotics and possibly involved with a major cocaine distributor."

"I feel there is something to the allegations against Mike, that they can and should be pursued from both avenues," Cox wrote.

City Manager Douglas Harman requested Friday that Commonwealth's Attorney John E. Kloch investigate the allegations that Strobel prematurely called off the police drug investigation.

Kloch declined that role yesterday, saying he was "not an investigator."

Instead, he turned over to the regularly scheduled grand jury what he called "the collection of information and allegations" relating to the drug investigation, asking it to call for a special grand jury. It did, and Judge Kent agreed to impanel the jury.

Under Virginia law, special grand juries are empowered to conduct investigations, but not to issue indictments. They typically are assisted in their inquiries by a special prosecutor named by the circuit court judge.

Special grand juries have subpoena power and can call witnesses. They meet in secret and issue reports that can be used as the basis for indictment by a regular grand jury.

Kloch said yesterday that he will not be present when the grand jury considers the testimony of any witness, and he recommended that special counsel be designated immediately.

Kloch said he expects the grand jury to begin sitting next week and to take two to three weeks for its investigation. As "an autonomous and independent body, it may inquire into any matter consist with its mandate," he said.

He said that "if these same allegations prove to be unfounded, their falsity must likewise be exposed in order to ensure the continuation of good government."

Kloch was approached in October by Cox and two other police officers and asked to examine the handling of the drug investigation. After a review of the materials, Kloch concluded there was no evidence of criminal wrongdoing on Strobel's part.

Harman, who had opposed a vote by the City Council to hire a Washington attorney to conduct an independent inquiry, said yesterday he was pleased by Kloch's decision.

"It seems to me that the procedure really provides for everything that people have been indicating that they wanted," Harman said.

Harman has been drawn into the matter because he is Strobel's superior. Some council members have voiced concern that neither Strobel nor Harman informed them of the continuing drug investigation and its focus on Norris at a time when they were discussing a merger of the police department and the sheriff's office.

Mayor Charles E. Beatley, who had said the matter would eventually have to be investigated, said the announcement of a special grand jury came as a "complete surprise."

In a statement, Kloch said yesterday: "Serious allegations of improper conduct, malfeasance, and nonfeasance in office have been made . . . . If these allegations are true, in my opinion, there may exist a condition which involves or tends to promote criminal activity."

Investigator Cox, who left the police force in August, said yesterday that he was told to conduct the drug investigation in secret and that only three persons at the police department beside himself were aware of it: Strobel, who was then the police chief, plus Bratcher and another officer who was on the investigation with him, Phillip Adcock.

Cox said yesterday he was aware the investigation was targeting Norris "from the very first day I received information." He said that during the time the City Council was discussing a merger of the sheriff's office with the police department, Bratcher was asking for "something on Norris, if there's something."

The City Council was considering the merger from February until late April, when it voted to go ahead with the change.

Cox said it was his understanding that the entire investigation, which centered on the popular city restaurant Marco's Cafe on South Washington Street, ended in April, shortly after a new owner took over.

At that time, Cox wrote in the memo, "To date, the investigation has in fact infiltrated a major narcotics distribution operation. Cocaine purchases have been made, with excellent possibilities of making larger buys, which would lead to the arrest of the backer of the operation."

Strobel told City Council last Thursday that he had never read Cox's April 20 memo. The public safety chief has staunchly defended his handling of the drug investigation, saying that on Dec. 21 the probe was continuing and that if he made errors, they were errors of judgment.

Strobel has repeatedly said the investigation turned up no evidence of criminal wrongdoing on Norris' part.