Democratic mayoral nominee Sharon Pratt Dixon enjoys a commanding lead over Republican rival Maurice T. Turner Jr., according to a survey of 600 likely District voters conducted for WJLA-TV (Channel 7).

The poll, conducted this week and released yesterday, showed Dixon supported by 71 percent of the respondents, compared to 14 percent for Turner. The poll was conducted by KRC/Communications Research and had a margin of error of plus or minus 4 percentage points.

Meanwhile, Turner defended his ownership of three handguns, even though D.C. officials say the city's stringent gun control law includes no exemptions for retired police officers to own such weapons.

"I don't believe it's in violation of the law," Turner told WJLA. "Those are my handguns. I bought them legally and lawfully . . . I intend to keep those."

Turner, who retired as D.C. police chief last summer, said he could keep the guns because he bought them while a police officer and "the law does not allow me to give back to the government something that I lawfully purchased."

In August 1988, the District's corporation counsel said in a memorandum that city law "does not allow a law enforcement officer to continue to legally possess a firearm in the District after he or she ceased to be a law enforcement officer."