A D.C. Superior Court jury yesterday convicted two men of murdering Gloria D. Whipple, the 51-year-old Washington artist who died in 1979 after she was brutally beaten during a robbery on the Mall. The jury also convicted the two men of murdering a Navy petty officer during a robbery at his Southeast Washington apartment two hours after the Whipple beating.

Convicted were Roy Anderson Leasure, 20, and Charles Patterson Perkins, 20 both of Southeast Washington. Each could be sentenced to a maximum of life imprisonment.

Prosecutors charged that Leasure accosted Whipple sometime around 10 p.m. on Sept. 17, 1979, as she was walking to catch the Metro after attending a puppet-making class at a Smithsonian Institution art gallery. Leasure beat her to the ground and raped her after he discovered that she was not carrying much money, prosecutors said. Perkins, driver of a getaway car, stood by and assisted Leasure, according to prosecutors.Whipple died 18 days later after being in a coma at George Washington University Hospital.

The trial was interrupted briefly when Judge Carlisle E. Pratt denied a government attempt to introduce as evidence a statement made by Whipple that she was raped during the attack -- a statement prosecutors argued was essential to their case.

Pratt had ruled that Whipple's statement, which she made to a U.S. Park policeman who found her after the attack, possibly had been "fantasized." However, the D.C. Court of Appeals, meeting in an emergency session, overruled Pratt and permitted the statement into evidence.

Leasure also was convicted of raping Whipple. Perkins was acquitted of the rape charge.

"These two men spent two hours that night robbing . . . burglarizing and killing," prosecutor Paul N. Murphy said in his closing argument to the jury Thursday.

The government's case was built largely on the testimony of two assocates of Leasure and Perkins who became government witnesses in return for pleading guilty to lesser charges connected to the case. Murphy and assistant U.S. Attorney Richard C. Otto also attempted to bolster the case with physical evidence, including palm prints of Leasure's that were found next to the body of Navy petty officer George K. LaRoach, 34. LaRoach had been strangled and drowned in the bathtub of his apartment at 2300 Good Hope Rd. SE.

Whipple moved to Washington in 1975 and joined the city's small but active art world. She taught graphics at an area college and was active in various art organizations.