A D.C. Superior Court jury convicted a 23-year-old Northwest Washington man yesterday of assault, armed robbery, burglary and other charges in connection with attacks on five elderly women in neighborhoods near the man's home.

Stanley R. Rice, of 3001 11th St. NW, was indicted Oct. 15 for a series of robberies and sex offenses against women between the ages of 75 and 85 that began in August 1978 and ended last July.

In an eight-day trial, five of the women described in testimony how a young man entered their homes at various hours of the day, struck them with his fists or weapons, demanded sex and money, then fled.

An 85-year-old witness, testified she heard a noise at her back door on the evening of July 15. When she went to check the door, a man pushed his way inside her home, ripped off her clothing and tried to have sex with her, she testified.

The woman testified that her assailant struck her repeatedly with a flashlight and threatened her with a knife. She said he took several hundred dollars from her home during the incident.

Another elderly witness testified she went out on her back porch about 7 a.m. last March 23 to look for her dog. She said she brought the animal's bowl back inside her kitchen, then went to a second floor bathroom to get medication for her high blood pressure. When she returned to her kitchen, the woman said she was confronted by a nude man wielding a screwdriver. She said the man forced her to a bedroom and attempted to have sex with her. Before leaving her home, she said the man took jewelry and forced her to remain in the basement until he was out of the house.

Rice's attorney, John Shorter, did not call witnesses in Rice's defense and Rice also did not testify.