Major crimes reported in Washington dropped 7 percent in 1984, marking the third consecutive year of decline, D.C. Police Chief Maurice Turner said yesterday.

"I think [the decline] is a result of crime prevention programs, neighborhood watches and the help of the U.S. attorney's office on repeat offenders," Turner said in an interview.

There were 53,857 major crimes reported in the District last year, compared with 58,150 in 1983. The 1984 total was the lowest since 1979, according to police records.

Reported crime in surrounding jursidictions is mixed. Crime dropped 6 percent in Alexandria last year, and increased less than one percent in Fairfax County. Montgomery County reported a one percent increase, while Prince George's County reported a 5.3 percent decrease.

In the District the sharpest decrease was in robberies, which were down 21 percent, Turner said. Burglaries fell 12 percent, rapes 10 percent, and larceny 7 percent.

Only aggravated assaults and auto thefts showed increases, up 12 percent and 11 percent.

In 1983 aggravated assaults increased by a single case over 1982, to 3,646. Last year 4,097 cases were reported.

Gary Hankins, spokesman for the D.C Fraternal Order of Police, tied the increase in assaults to a greater number of victims reporting crimes.

"In the noncriminal areas I think what we're seeing is a greater awareness of those who are victimized by violent attacks who are reporting them, whereas before there was sort of a helpless sense."

Although Hankins said increased public cooperation has helped curtail crime, he cautioned that the increase in numbers does not accurately mirror gains made in reducing crime.

"I think we're just beginning to see a turnaround in crime," he said. "However, it's nowhere near an acceptable level. It's like telling a drowning man in a swimming pool that you've bailed out a couple of buckets of water. I'm afraid that what we're seeing is about the limits of community resources."

Hankins was also critical of what he called police strategy to push criminals from one part of the city to another. "All we're able to do is move our downtown crime to the 7th District [far Southeast]."