Just a few years ago, Deputy Chief Isaac Fulwood Jr. was under fire, his leadership of the 6th Police District questioned in two controversial and divisive investigations.

Today, as assistant chief for field operations, considered the number-two post in the D.C. police department, he is widely perceived as one of the leading contenders to succeed Police Chief Maurice T. Turner.

Fulwood, a 44-year-old D.C. native with graying hair and an easy manner, says that in his current position as chief of the day-to-day operations of the police force, with more than 3,400 officers under his direct command, he will make the war on illegal drugs his top priority.

"Drugs are the driving force behind crime in the city," he said. "If we don't win the war against drugs, chances of continuing the success we have had in reducing crime diminishes . . . . We have to come up with as many approaches as possible."

Fulwood was promoted Dec. 31 when Assistant Chief Marty M. Tapscott was abruptly transferred to head the technical services bureau, a less influential and less prestigious post.

The announcement came from Mayor Marion Barry's office, not Turner's, fueling speculation that the mayor had handpicked Fulwood. Barry, noting that 35 other promotions and reassignments were announced the same day, said his office wanted to highlight the promotion of Joyce F. Leland, the District's first female deputy chief.

The Fulwood-Tapscott switch has created a rift among black police officers, many of whom look to both as role models and are distraught over the way Tapscott was unceremoniously shoved aside. The day of the announcement, Tapscott, 48 and a 25-year veteran, angrily said the transfer was handled "without integrity . . . . That's the reward you get for working hard."

Other police officials critical of the move point to a 1982 departmental investigation and a probe by the U.S. attorney's office last year that raised serious questions about Fulwood's command of the 6th District. Both investigations cleared him of any wrongdoing.

"The U.S. attorney's office investigation, the police department's investigation, both came out and said I never did anything wrong," Fulwood said. "Why does everyone always want to talk about those two reports?"

Turner also said he didn't have to "justify" Fulwood's promotion.

"As the top administrator of this department, I felt a change was needed . . . . I like his Fulwood's management style. It's similar to mine. He's a good manager and motivator."

Noting that the post of field commander is a "tiring job," Turner said Tapscott had been in the position for 3 1/2 years and Fulwood can provide "new thoughts and new ideas."

During Tapscott's command of field operations, which includes all seven police districts, three divisions, 85 percent of the department's manpower and 72 percent of the department's budget, the city posted a 22 percent reduction in serious crime.

Now that responsibility falls on Fulwood's shoulders.

"I'm well prepared for this new job," Fulwood said, ticking off his previous assignments: community relations, personnel, tactical services, internal affairs, financial management, commander of two police districts. "I may not be perfect, but I give 110 percent, and that means I do a fairly decent job."

Fulwood was raised on Capitol Hill and graduated from Eastern High School. He now lives in Temple Hills with his wife Ruth, his 19-year-old son Gary, and his daughter Angela, 16.

He joined the police force in 1964, when there were few blacks in the department. It was Turner, then a sergeant and one of the highest ranking blacks on the force, who encouraged him to study hard for promotional exams.

Fulwood began a steady climb up the department's ladder and was promoted to sergeant in 1971 and lieutenant in 1975. While a lieutenant in the 1st District, he was one of the officers who aided Barry, then a City Council member, after he was shot during the 1977 Hanafi Muslim attack at the District Building.

It was under former police chief Burtell M. Jefferson that Fulwood enjoyed his most rapid ascent, rising from lieutenant to captain to inspector to deputy chief in just 26 months.

Fulwood was the first black in the department's history to have a decision-making role in the office of financial management, where he earned a reputation as a tough manager. As a captain and inspector in that office, he frequently had to deny requests for money from his superiors.

"You have to say no and you have to take a lot of abuse," Fulwood said of the job. But he added, "We were fortunate. We never overspent."

As president of the Organization of Black Metropolitan Police Officials, Fulwood was one of Jefferson's most vocal supporters when the former chief complained about what he considered Barry's interference in the department.

When Jefferson resigned in 1981 and Turner became chief, Fulwood, a confidant of Jefferson, was transferred to the 6th District in far Northeast. He stayed there until he was moved in May to the 1st District, his last assignment before his promotion to assistant chief.

Community leaders who attended 1st District civic meetings with Fulwood said they found him abrasive and not always receptive to the needs of their community, which includes Capitol Hill, the neighborhood where he grew up.

But as commander of the 6th District, Fulwood appeared to enjoy extraordinary support from political, community and business leaders. He called his command of that district "one of the most rewarding experiences of my career."

But it was also a time of low morale, racial tension and undeniable upheaval among the rank-and-file officers, largely because of two widely publicized investigations of the district.

One investigation by the police department's Internal Affairs Division centered on allegations by officers in Fulwood's command that they were ordered to "downgrade" serious crimes to lesser offenses, thus showing a drop in 6th District crime that existed only on paper.

After months of inquiry and hundreds of interviews, the chief investigator issued a 117-page report that concluded that the downgrading "policy" had "very damaging effects within the department" and "has certainly been shown in this investigation not to be in the best interest of the safety and welfare of the citizens of this community."

Community leaders backed Fulwood. Tapscott attributed the reclassification of crimes to "poor judgment" and cleared Fulwood and all other police officials in the investigaton, saying the downgradings were not done with "devious intent."

In a recent interview, Turner said he "thoroughly reviewed" the report and agreed "wholeheartedly" with Tapscott's ruling. "I thought the report was biased to begin with," he said. He would not elaborate.

About a year later, Fulwood was cleared in another investigation by the U.S. attorney's office into allegations that 6th District officers organized and participated in a carnival featuring illegal gambling games, held to raise defense funds for an officer charged with shooting a man while off duty.

In a June 1984 letter summarizing his findings, U.S. Attorney Joseph E. diGenova declined to prosecute anyone in the case, but wrote that his investigation revealed "shockingly poor judgment" on the part of police officials involved. He did not mention any officials by name.

Mayor Barry said recently that the letter "reflected poorly on diGenova's politicking in the police department. That's how I viewed it and that's how the police chief told me he viewed it."

At his Temple Hills home, Fulwood shook his head when asked about diGenova's letter. "Reasonable men can disagree," he said.

"I'm a family man. I walk alone. I don't go to parties and I rarely drink," he said. "I have over 130 commendations . . . . The D.C. City Council passed a resolution for me.

"I've had advantages others haven't had," he said. "That's not to say there aren't other deputy chiefs who aren't qualified to be field operations commander."

But, he said, "When you examine Isaac Fulwood, most people will say this is not a bad guy."