Mayor Marion Barry, reacting to a slaying and incidents of rowdiness and fighting at Washington's New Year's Eve celebration last week, said yesterday he may ban the sale of liquor at future celebrations and introduce entertainment aimed at attracting families.

"We want to draw a cross section, more families," he said in response to assessments that the New Year's event at the Old Post Office Pavilion primarily had attracted a youthful crowd that got out of control after midnight.

Barry, who attended the event with his wife Effi, said he was unaware that liquor was sold during the celebration and that he would have disapproved if he had known.

"It's the first I've heard of it," he said. Barry noted that at the city's summertime Riverfest celebration, vendors sell beer but no hard liquor and suggested that a similar policy might be introduced for New Year's Eve. Vendors sold beer, wine and liquor at last week's celebration.

The mayor's remarks came as he honored five police investigators for their quick action in solving the slaying of Marquita Vaughn, 18, whose body was found in a remote stairwell of the pavilion after the celebration.

The mayor said he was "not ready to cancel" future celebrations and hoped the event begun three years ago would continue to grow. He said other New Year's celebrations around the country also were marred by scattered arrests and violence.

D.C. Police Chief Maurice T. Turner Jr. said the department next year would add 100 to 150 officers to the approximately 310 officers deployed this year.

Turner said a report on the New Year's Eve disturbances, in which 15 arrests were made, was being prepared by his department and the D.C. Office of Emergency Preparedness. An assessment of future New Year's Eve events will be based on the police report and comments from the Mayor's Committee to Promote Washington, which organized the event, Barry said.

The mayor said the city may provide a different mix of entertainment in future to draw a cross section of celebrants to the activities. Band leader Cab Calloway headlined the entertainment indoors this year, attracting different age groups. The outdoor show, attended mostly by younger people, was headlined by soul singer James Brown and included such groups as Willie Colon, the Del Fuegos, Experience Unlimited and On Beyond Zebra.

During the ceremony, in which he presented the officers with certificates of appreciation, Barry asserted that the New Year's celebration had been a success. He conceded, however, that "there will be some who would try to link the tragedy to the festivities."

Vaughn was found strangled about 2 a.m. on New Year's Day. Alex Tyrone Simmons, a 20-year-old Wheaton man who police said met Vaughn at the celebration, was arrested last Thursday and charged with felony murder.

Barry said he was honoring the investigators because he "felt so moved by the speed" with which the police solved the case. The officers honored were Sgt. Henry Daly and Detectives Joseph Schwartz, Rocco Cianciott, Clayton Bagley and Ronald Taylor.