A 22-year-old woman was found beaten and strangled with her bathrobe cord on a couch in her high-rise apartment in South Arlington Sunday night. Nearby was the decapitated body of her parakeet which detectives theorize was slain out of fear that it could speak and identify the killer.

Yesterday police arrested a 20-year-old Northwest Washington man and charged him with murder after learning that he and the woman apparently had met Friday night at a popular Southwest Washington disco and had been seen leaving the disco together.

Both the woman, Joyce D. Robertson of 2300 S. 24th Rd. and the suspect, Skip Adams Taylor of 2700 Cathedral Ave. NW, were frequent patrons of the disco, Pier 9 at 1824 Half St. SW, according to police.

Police said that the motive for Robertson's slaying apparently was robbery.

They said they found stero equipment from her apartment in Taylor's apartment.

Robertson, a clerk at Arlington Paper Supply, was discovered shortly after 10 p.m. Sunday by friends who became concerned after she failed to answer the telephone.

The head of Robertson's parakeet had been torn off, according to investigators.

Police put the time of death at noon Saturday They said a friend reported speaking with Robertson by phone Saturday morning and being told by her that she had a guest in her apartment.

Police said Robertson's body bore many bruises apparently inflicted with a small whip. When found she was lying face up on the couch wearing a purple bathrobe. Authorities said that they are conducting tests to determine whether Robertson had been sexually assaulted.

When arrested police say the suspect also bore marks indicating he may have been whipped.

Robertson lived with two other women in a two-bedroom 10th floor apartment in the Dolley Madison Towers which overlooks the golf course of the Army-Navy Country Club. Police said her roommates were away for the weekend.

Robertson had worked for six months at the paper company, whose owner, Joel Olcott, described her as "very pleasant, very nice."