An elderly Southeast Washington couple and the wife's deaf sister, all described as quiet and polite, were found murdered yesterday in the blood-spattered house they shared at 3028 P St. in the Randle Highlands section.

At least two of the victims had been shot, police said. The third may have been stabbed, according to a preliminary account.

They were identified as John Covington, 68; his wife, Virdell, and Mrs. Covington's sister, Carolyn Bruton. Both women were in their 60s. Many neighbors on the quiet street of 13-year-old detached brick-and-concrete houses said they had often greeted the three, but knew little about them.

No motive could immediately be learned for the slayings, which followed by six days the fatal stabbings of an 85-year-old woman and her 61-year-old daughter in their home in Northwest.

Preliminary investigation at the scene of yesterday's killings showed no indications of forced entry, police said. A police spokesman said witnesses had reported seeing two men visit the house during the afternoon.

Police said last night they had made no arrests and had no suspects. No arrests have been made in last week's slayings.

Police were called to the house on P Street about 4 p.m. yesterday after being alerted by Herbert Grier, described as the Covingtons' son.

Blood was splattered all over the interior of the house, according to Deputy D.C. Medical Examiner Dr. William Brownlee. Authorities released little other information about the condition of the house or of the bodies.

All the victims apparently suffered wounds in the head and neck area, according to a detective in the 6th Police District, where the house is located.

Many neighbors interviewed last night provided descriptions similar to that of a woman who said the residents of the house would pass hers and "wave at me."

"I'd never visited them and they never visited me," the woman added.

"They seemed to be very nice people," she said, "that's all I know."

A city directory for 1973 listed Covington as a plumber's helper with the Noland Plumbing Co. A Noland official, contacted last night, said he recalled an employe named Covington as having retired a few years ago.

Neighbors said the Covingtons had live on P Street since the homes there, now assessed in the $55,000 range, were built in 1965.

Bruton, who was deaf, according to nearby residents, was a familiar figure to many, and was often seen walking with her two small dogs, a Pekingese and a poodle. She was said to be active in a church a few blocks away. A neighbor said he last saw her Wednesday night.

"My dog and hers walked home together," the neighbor said. Bruton was deaf, but not mute, neighbors said, and could communicate with them.

The neighbor said Mrs. Covington had occasionally spoken of trips she made through North Carolina while playing basketball as a college student.

The husband, according to the neighbor, was generally "coming and going all during the day." However, the neighbor said, he did not see Covington yesterday.