Democratic mayoral candidate Sharon Pratt Dixon and Republican candidate Maurice T. Turner Jr., in an appearance that highlighted the deep differences between them, clashed last night over police tactics and the merits and failings of their political parties.

But in brief comments after a candidates' forum, they agreed on one matter: their opposition to President Bush's veto yesterday of the Civil Rights Act of 1990.

Turner, who had changed his party affiliation before announcing his candidacy and has been endorsed by Bush, said he went to the White House yesterday and met with a presidential aide to argue against the veto. Dixon said it was unbelievable that the bill was "even an issue" at this stage in the nation's history.

Earlier during the forum, sponsored by three lawyers' groups and held at the Howard University Law School, the candidates continued their recent skirmishing over several contentious issues, including methods of dealing with crime and Dixon's former connection with Potomac Electric Power Co.

Turner, outlining his plan for fighting crime, called for expansion of the Lorton Correctional Complex and the creation there of rigorous, effective job training programs. "We can't continue to make excuses for people who violate the law," he said.

While asserting a need to "get tough on crime," Dixon argued that it also is necessary to get tough on its "root causes" rather than rely on what she called "empty macho Republican" talk.

In response, Turner lashed out at the Democratic Party, asserting, "It's been Democrats who've been in charge of this {city} government for the last 20 years . . . Democrats setting policy."

"I was not a part of this Democratic administration. You were," Dixon told Turner, who was police chief for eight years.

Speaking at a time when the city's homicide rate is again reaching record levels, Dixon expressed a need for "major reform in the police department." She urged that officers leave scout cars and desk jobs to begin walking beats and become "part of the fabric of the community."

But Turner said that more officers are needed, telling about 100 people attending the forum that the volume of calls for police assistance is so high that officers on foot are "not going to get to you."

In response to a question about help for people who could face rent increases caused by a rise in fuel prices, Turner said he "would hope nobody heats by Pepco" because electric bills would "go through the roof."

In an impassioned rejoinder, Dixon, a former Pepco vice president, said voters deserve "honest dialogue without scurrilous attacks without basis in truth." She later said she interpreted Turner's remark as a personal attack.