A 24-year-old Capitol Heights woman was killed and her 34-year-old companion was seriously wounded early yesterday when both were shot in the head, apparently as they slept inside the woman's apartment, Prince George's County police reported.

Police said Sheila Marie Bannister was shot about 2 a.m. by a man who entered her apartment at 1408 Nova Ave. through a bedroom window. They said Bannister was pronounced dead at the scene.

Police said Thomas R. Long of 2216 Matthew Henson Ave., Palmer Park, was wounded in the shooting. He was listed in serious condition last night at Doctor's Hospital with a bullet wound in the head.

According to police, Bannister, Long and another man had been visiting with one another in Bannister's apartment late Thursday night. They said a quarrel developed and the man left.

Later, while Bannister and Long were sleeping, police said, the man returned with a gun and removed a bedroom window screen to enter the apartment. After shooting Bannister and Long, police said, the man fled.

Despite his head wound, police said Long managed to reach a friend's house and report the shooting.

Police last night arrested a neighbor of Bannister's, Alfonso Taylor, 55, of 1410 Nova Ave., and charged him with homicide and assault with intent to commit murder.

Taylor was being held without bond last night at the county detention center.