In the end, even Alexandria Police Chief Charles T. Strobel's staunchest supporter could not defend him.

Mayor James P. Moran bet his political career on Strobel in 1985, backing him through a mean season when opponents wanted the chief in jail. But last week, when Strobel stepped down amid the glare of yet another investigation, Moran simply said goodbye. "It's now time," Moran remarked with an air of finality, "to move on to a new chapter."

Strobel, citing "stress and strain," began permanent leave from his job Wednesday, marking the conclusion of 10 tumultuous years as chief. The day he left, city officials released a report that cited "significant failure of top management in the Police Department." Strobel has made no comment on the report since his departure.

In interviews last week, city leaders said Strobel's departure climaxed much more than one man's career.

His absence, they said, ends an era in which Strobel's performance was the dominant political issue in Alexandria, bitterly dividing the City Council and toppling a longtime mayor.

Leaders also predicted that it will begin a new day for the troubled Police Department. City Manager Vola Lawson will move to put her stamp on the department, they said, and doors will open to fresh leadership.

"This was the right decision," said council member Redella S. (Del) Pepper. "I think we're starting the process of straightening things out in the Police Department. And then we're going to move on."

"Charlie reminds me of a fighter who was beaten up so badly in the first eight rounds that all he could do for the last two rounds was hang on and clinch," Moran said. "I had hoped it would end differently. But this just took all the stuffing out of him.

"Turmoil in the Police Department has been a terrible distraction" for the city, Moran said. "We can now look ahead to more important concerns."

There has also been growing impatience with what Moran called "favoritism and intransigence" among senior police officials. Strobel and many of the department's senior officers have served for more than 20 years in Alexandria; Moran questioned whether friendship sometimes outweighed professional concerns.

"We have too much nepotism and cronyism, and a change is needed to clear the air," said Investigator Barry Schiftic, president of the Alexandria Police Association, a labor organization. Schiftic said a recent poll found that 75 percent of the group's members hope Strobel's successor will come from outside the department.

Lawson is already laying the foundations for major change in the department. The search for Strobel's successor is under way, and Lawson hopes to have the new chief in place by Dec. 1. Acting Chief Arlen Justice has begun a review of the department's management structure and will send his analysis to Lawson by Nov. 1.

When Lawson lists the qualities she is looking for in a new chief, she touches on the same areas that council members now cite as problems in the department.

"Can they {job candidates} manage effectively?" Lawson asked. "Are they credible in all segments of the community? Are they committed to training and retraining on the job? Are they sensitive to minorities and women?

"We want a Police Department the composition of which reflects the composition of the community, not only because it's morally right but because it's good common sense," Lawson said. "We're going to go through an exhaustive selection process to find a chief. And we're going to find somebody who is really experienced and ready to take over."

The final episode in Strobel's career began two weeks ago and centered on one of his department's most sensitive tasks, drug enforcement. An internal probe launched by Lawson found that Strobel and one of his veteran commanders, Lt. Arthur L. Bratcher, failed to pursue an allegation of wrongdoing against a former narcotics officer.

According to the investigation report, a confidential informant charged this spring that the narcotics officer, David B. Goldberg, had tipped off an acquaintance who was targeted in a drug probe. The report said that neither Bratcher, who learned of the allegation in early May, nor Strobel, who was told in mid-June, started a formal inquiry until mid-July.

The investigation did not find enough evidence to bring charges against Goldberg, but a criminal probe of his actions is continuing. Goldberg's attorney has said his client did nothing wrong.

Bratcher, who was stripped of his job as commander of the vice and narcotics unit, has not been available for comment. Strobel's attorney, David Ross Rosenfeld, has declined to discuss the internal investigation and "any discipline the city may have taken" against Strobel.

For most of this decade, Strobel has found himself at the center of a storm. In 1983 the city's police and fire departments were combined to form a public safety division and Strobel was appointed to head it. The merger worked out so poorly that it was undone six months later.

During his tenure as head of the safety division, Strobel appointed William H. Pennell Jr., a former police sergeant, to head the city's code enforcement division. In June, Pennell was demoted and three inspectors were fired after a five-month internal investigation of conflict of interest allegations.

A 25-page report on the investigation included a blistering criticism of "senior management," in part for its failure "to recognize in a timely manner the extent of the conflict-of-interest problem."

In 1985 Strobel and two of his officers filed lawsuits against each other, with the officers charging that Strobel had transferred them without cause and Strobel charging that the officers had defamed him. Both sides were awarded damages.

But it was also during that year that Strobel's darkest moment came.

Police officers charged that Strobel had squelched an investigation into drug use by prominent Alexandrians. Then-Mayor Charles E. Beatley Jr. demanded an investigation of Strobel. Two lengthy criminal investigations were launched, and Strobel spent several months away from his office on paid leave.

Eventually Strobel was exonerated and a grand jury blasted city leaders for politicizing the inquiry. Moran challenged Beatley, a former political ally, making a defense of Strobel his primary campaign issue and hammering away at Beatley's role in the Strobel probe.

After an unusually caustic and personal campaign, Moran broke Beatley's 15-year hold on the mayor's office. Civic leaders took to disparaging the entire affair as a "two-bit scandal," and Strobel seemed to have his vindication. But it was not to last.

"I felt confident defending Charlie Strobel at that time, because he had been accused of criminal things that didn't bear up under scrutiny," Moran said. "But I knew he had management deficiencies even then.

"The City Council was willing to give him a fresh start as a manager. Unfortunately, after all the unpleasantness, he never really returned to his office. The lights were on, but all too often no one was home."

Vice Mayor Patricia S. Ticer said: "It's not so much what the chief did, it's what he didn't do. After he was cleared, he had a golden opportunity to take care of his shortcomings. But he just didn't take hold."

Council members and city officials point to several long-running problems that they said Strobel failed to effectively address. The one most often mentioned is drugs, particularly burgeoning street drug sales in the city's poor neighborhoods.

The City Council recently appointed a high-profile task force to combat the drug problem, but was embarrassed when the latest internal probe found that only two officers were actively investigating city drug sales. They have also expressed concern that the two police squads handling most drug cases have no black members.

Since Lawson was named city manager in 1985, she has clashed frequently with Strobel. Now she says she hopes her days of detailed involvement in law enforcement are coming to an end. "I don't think the city manager ought to be running the Police Department," Lawson said.

"The changes that have been made are going to help with the stability there. The police officers who have joined the force in the last 10 or 15 years reflect the fact that the country has become more enlightened. There are some really excellent people over there, and we want to let them do their jobs."

Moran said: "We need someone who knows what they want, a leader who can lead by example. Many of the police officers have lost confidence in their supervisors, and that needs to be restored.

"There is a lot of trust and confidence and professionalism among the officers down in the ranks. We want to give them a chief they can feel the same way about."