BOSTON (AP) _ A man who had told police he killed two elderly women but was released when he couldn't find their house again faces psychiatric evaluation after his lawyer argued the man was suffering the stress of duty in Vietnam.

A plea of innocent was entered Tuesday for Ronald A. Guest, 37, who was charged with murder, assault with intent to murder and assault and battery with dangerous weapons, a hammer and a knife.

Guest surrendered Monday, a day after the victims' bodies were found and two days after he originally told his story to police. He was ordered Tuesday to Bridgewater State Hospital for 20 days observation.

''He's had problems since coming back from Vietnam,'' said court-appointed lawyer Philip A. Tracy Jr., who declined to elaborate. Tracy said Guest was an unemployed laborer.

Peter Gallagher, a Quincy police officer and family friend, said Guest appeared drunk and frightened when he took Guest to Boston police headquarters.

The family had asked Gallagher to pick Guest up at a subway station near downtown Boston on Monday and accompany him to headquarters.

''I've never seen him violent,'' said Gallagher, who has known Guest for four years.

Police said a man they believe was Guest called them Saturday afternoon about the killings in the Dorchester section of the city. Guest showed up at police headquarters late that night, drunk and talking about the slayings, Detective Mary Evans said.

He was released because he could not lead police to the house he claimed held the victims, Evans said.

''Everything was done according to law,'' said Boston Police Commissioner Francis X. Roache. ''Everything was done as it should be.''

On Sunday, the battered bodies of Velma Goodwin, 85, and Harriet Cady, 75, were found in the house Mrs. Goodwin owned. Her daughter discovered the bodies of the two longtime companions after no one answered her calls to the house.

A badly beaten man, George Harvender, 62, was found in the basement of the boarding house.

Police said nothing was missing from the house and there was no sign of forced entry.