When Edward T. Norris left New York three years ago, many wondered why he would abandon a promising career at a prestigious police department to join the struggling Baltimore force.

Now that Norris is leaving Baltimore to become Maryland's state police superintendent after establishing what appears to be a successful crime-reduction plan, many again are wondering why.

Norris says he wants a new challenge. Others suggest that the former commissioner is leaving the city while his star is still on the rise.

Regardless, it might be too early to determine the lasting effects of Norris' crime-fighting tactics and his re-engineering of the department. In the past three years, statistics show the city has registered a significant drop in crime - a 29 percent reduction - and homicides have remained below 300 each year after exceeding that mark during the 1990s.

Yet Baltimore remains one of the most violent and deadly cities in the country. And while departmental morale seems to have significantly improved under Norris, many officers question whether the agency can retain its focus and sustain its energy after such a sudden departure. Even so, most inside and outside the department say Norris has left a lasting mark.

"He was one of the best police commissioners Baltimore has ever had," said former Deputy Police Commissioner Bert F. Shirey, who left the force in January after 35 years.

Norris' tenure was as much characterized by his flamboyant style as by his tactical decisions and personnel moves.

He arrived a tough-talking New York City police commander who was a former amateur boxer and an avid weight-lifter. He had a reputation for gruff leadership, often grilling his commanders about street-level performance.

But Norris also has sophisticated tastes, enjoying regular manicures, shopping in Manhattan boutiques, and dressing in tailored suits. Charming in social settings, he persuaded executives and civic leaders to donate millions of dollars to a private anti-crime foundation.

Norris, 42, who has the build of an oil drum, started as the department's second-in-command to then-Commissioner Ronald L. Daniel. He had barely started when Daniel quit after only a few months in office, and Mayor Martin O'Malley named Norris the city's top officer.

Norris said he was upset by the brazen nature of criminals who did not even seem to fear police officers. He quickly determined he made the right choice.

"I have this real burning hatred of bullies," Norris said in an interview earlier this year. "I just hate watching the strong pick on the weak - predatory people. Somebody has to protect them."

Norris immediately began carrying out strategies that he brought from New York, including:

Establishing a warrant task force to hunt down some of the city's worst fugitives before they could commit other crimes.

Dispatching detectives to district stations so they would get to know the areas where serious crimes were committed.

Creating the police foundation to raise money for badly needed equipment.

Implementing internal stings to weed out bad cops.

The most important initiative, though, was the Comstat program, which uses computer data in crime analysis and holds commanders accountable for results.

Many commanders recalled those first Comstat sessions, which they described as grueling with Norris demanding detail after detail about why auto thefts were up or why shootings were spiking or who was responsible for a string of burglaries.

The system appears to have worked. Soon, crime began to drop. After a decade in which homicides remained more than 300 annually, the number fell to 261 in 2000 and has remained in the mid-200 range since.

Yet not everyone appreciated Norris' approach. Many inside police headquarters said Norris was occasionally unapproachable or ill-tempered.

"I remember one [meeting] where he was just losing it on all of us," said one commander who requested anonymity. "It was such an insignificant issue that I can't even remember what he was yelling about. But it was 'm-this' and 'f-that.'"

While he was pushing commanders inside the department, Norris was meeting with community leaders, prosecutors, minority groups and business executives. He was at ease in any social milieu and was comfortable discussing almost any topic.

He eventually even wooed those initially concerned about his aggressive, "zero-tolerance" crime-fighting style.

"He was a jewel," said G.I. Johnson, president of the National Association for the Advancement of Colored People's Baltimore branch. "We're disappointed he's leaving. The job he performed was a job that was well-done and well-needed."

Norris' view of his job seemed to change when terrorists struck his hometown of New York on Sept. 11., 2001. Soon, much of his focus switched from crime-fighting to preventing a terrorist attack on Baltimore.

Until Norris redirected his concentration, Baltimore was on pace for another steep decline in homicides. But, through the fall and early winter, murders skyrocketed, and the city ended the year with 256 killings.

Norris, an emotional man, took the "terror attacks almost personally," said Shirey, Norris' deputy police commissioner at the time.

"In retrospect, we invested too much of our resources in" terrorism prevention, Shirey added. "There were a lot of urgent issues on the streets of Baltimore that were more immediate than possibility of another terrorist attack. I think he was appropriate to put some attention on that, but I think it lost us ground on the crime scene."

Norris used the attacks as a platform to criticize federal law enforcement efforts to investigate terrorist activities. He became a national spokesman for local agencies, testifying before Congress and appearing on national TV news programs to discuss the lack of federal cooperation.

But while Norris lashed out at federal agencies and others he perceived as opponents, including disgruntled employees, he was sensitive to criticism.

In March, a lieutenant who had been stripped of his command began attacking the racial makeup of the police structure. The officer even held a futile meeting with a state senator and others about finding ways to get rid of the commissioner.

Norris approached his subordinate after a state legislative hearing in Annapolis, jabbed a finger in his chest and said: "Lieutenant, you can have all the ... secret meetings you want, but I'm not leaving."

Norris suffered his most embarrassing moment on the job when, in August, a Sun investigation uncovered that he had used an off-the-books account to finance more than $150,000 in expenses. The receipts revealed that Norris had run up large tabs at some of the city's finest restaurants. He had taken several trips to New York that he said were for business although he could not remember many of the specific purposes.

On one trip he did recall, the commissioner spent nearly $2,000 on hotel rooms and food while he attended the funeral of an employee's relative - and interviewed for another job with a Long Island police department.

Eventually, Norris issued an emotional letter of apology that expressed his regrets for his "failings as a human being." O'Malley ordered an independent audit, which subsequently questioned several thousand dollars of the agency's expenses and Norris agreed last month to repay about $6,000 to the fund.

Since then, Norris has kept a low profile - until last week, when he decided to leave for the state police. Those who know Norris are still trying to completely understand his departure.

"Eddie's an enigma," said Sean R. Malone, who worked closely with Norris as a top adviser for the last three years.

"He's a very tough cop but at the heart a sensitive man. He is very charming and never shies from making a tough fight. But he doesn't really like to harm people. Through the force of sheer personality, he changed the Baltimore Police Department."