Alexandria City Manager Vola Lawson yesterday placed Police Chief Charles T. Strobel on permanent leave and stripped a veteran lieutenant of his command after an internal probe of alleged police misconduct found "significant failure of top management" in the department.

Strobel, 49, whose 10-year tenure as chief has been plagued by allegations of wrongdoing and mismanagement, vacates the post three months before his previously announced Dec. 3 retirement. His salary is $76,000.

The commander of the department's vice and narcotics unit, Lt. Arthur L. Bratcher, 54, was placed on paid leave while he decides whether to accept a transfer to the patrol division.

Lawson criticized Strobel and Bratcher for failing to act quickly on allegations that a former narcotics investigator, David B. Goldberg, had tipped off the target of an undercover drug probe. Although the allegations were made in early May, police officials did not begin examining them until mid-July.

Lawson, who began searching for Strobel's successor earlier this summer, said yesterday's actions "will be the beginning of a new era" in the department.

Lawson has had strained relations with Strobel since she became city manager in 1985 and has criticized the department for mishandling a number of incidents in recent years.

Although many ranking Alexandria officers have served in the city for decades, Lawson has sought candidates for chief from around the country.

During the investigation, Goldberg was asked to take a polygraph test, but quit the force Aug. 7.

Police officials said they had no evidence that could lead to charges against Goldberg, but that they had forwarded the results of their probe to a regional law enforcement task force for further investigation.

Goldberg's lawyer has said his client did nothing wrong. Strobel and Bratcher could not be reached for comment.

"Our investigation found that mistakes were made and administrative procedures were not followed" in dealing with the allegations against Goldberg, Lawson said in a prepared statement.

"Under any set of circumstances, this series of events represents a significant failure of top management in the police department.

"However, in light of the severe drug problems facing the city . . . this series of events was intolerable."

Lawson appointed Deputy Police Chief Arlen Justice, one of three Alexandria officers who has applied for the chief's job, to serve as acting chief until Strobel's permanent replacement is named.

Lawson said she hopes to have a new chief in place by Dec. 1.

She also appointed Lt. Alfred Levesque to succeed Bratcher as head of the department's vice and narcotics unit, ordering him to step up the city's drug enforcement efforts.

Even though the City Council has formed a task force to combat drug problems, the probe found that only two investigators are working on city drug cases.

"One of Lt. Levesque's top priorities will be to realign the duties of the 12 employes in the vice and narcotics section to place a greater emphasis on narcotics violations," Lawson said.

According to the investigation report, Bratcher ignored allegations against Goldberg, the former drug investigator, for about 10 weeks and Strobel ignored them for about a month.

The report said that on May 7 Bratcher was told of allegations by an informant that Goldberg had leaked information regarding an ongoing drug investigation.

Police department rules require that Bratcher tell Strobel about any allegation against an officer in his command.

According to the report, Strobel learned about the allegations in a meeting with other officers June 15.

"Despite this June 15 meeting, another month elapsed before an internal police department investigation began to look into the allegations," the report said.

Deputy Chief John Streeter, who helped conduct the probe, said that Strobel and Bratcher said they did not take any actions regarding the allegations because they did not think they had enough information.

"This allowed him {Goldberg} to continue to have access to confidential information about ongoing drug investigations and could have jeopardized the safety of other police officers and the effectiveness of the investigations," the report said.

Yesterday's actions cap a tumultuous three years for Strobel and his department.

Since 1985, he has been the subject of two grand jury investigations.

Although he was exonerated of any wrongdoing, municipal officials say privately that lingering allegations crippled his effectiveness as chief.

The department also has been hampered by personality clashes -- in 1985 Strobel and two of his officers filed lawsuits against each other -- and by strained relations between Strobel and Lawson.

In recent days, city officials also have expressed concern that the department has lagged in minority hiring.

Strobel, who began his 29-year career with the Alexandria force as a patrol officer, was promoted to police chief in 1977.

Controversy has seemed to stalk Strobel since 1983, when then-City Manager Douglas Harman merged the police, fire and code enforcement divisions into one Public Safety Department and named Strobel its director.

The result was disarray.

The popular fire chief, Charles H. Rule, was so miffed that he retired. Police officers and firefighters, who suddenly had less upward mobility, complained of divisive rivalry and some of the resentment settled on Strobel.

Twenty months later, Lawson, who succeeded Harman, acknowledged the merger was a mistake and announced she would dismantle the new department, with Strobel returning as police chief.

For Strobel, 1985 was a particularly difficult year.

A U.S. District Court judge appointed a special grand jury to hear allegations that Strobel improperly halted a cocaine investigation.

He was placed on administrative leave as city officials criticized his performance.

The special grand jury not only cleared Strobel of any wrongdoing, but it also issued a report that blamed the "callous, politically motivated activities of certain members of the Alexandria City Council" for the "attempt to assassinate the character of . . . Strobel."

Not the least of his ongoing troubles was the 1985 appointment of Lawson as his boss.

The two were never friendly and at times, city officials said, Lawson and Strobel barely spoke.

Last year, a federal grand jury, which also had been investigating Strobel on his role in an abruptly halted police cocaine probe, indicted the police chief on charges of perjury and obstruction of justice.

After a federal jury acquitted Strobel of those charges, his attorney Plato Cacheris commented: "This case was a defense lawyer's dream: an innocent client and a bum rap."

Few were surprised on March 2, when Strobel announced he would retire Dec. 3 and move to Fredericksburg.