JACKSONVILLE, Fla. (AP) _ A Navy sailor was convicted today of killing a young woman and her daughter, slayings he blamed on the trauma of the 1987 Iraqi attack on his ship, the Stark.

Prosecutors argued the stress suffered by Walter Thomas Taylor Jr. when the USS Stark was struck four years ago was no excuse for the crimes, which took place days after the ship returned to port.

But defense attorneys said in closing arguments that Taylor was temporarily insane and experiencing a flashback that convinced him the woman was an Iraqi agent trying to kill him.

The jurors took 6 1/2 hours over two days before returning two first- degree murder convictions late this morning in the August 1987 deaths 21- year-old Paula Smits and her 3-year-old daughter, Amanda.

The same jury will now have to decide whether to recommend the electric chair or life in prison for Taylor. The judge will decide the sentence.

Mrs. Smits' family sighed, then began sobbing as the verdicts were read. Taylor showed no emotion, but his mother and sister cried.

The defense has tried to spare Taylor from the death penalty by linking the murders to the May 1987 missile attack, which Iraq said were a mistake. Thirty-seven sailors aboard the Mayport-based Stark were killed.

In final arguments Thursday, Assistant State Attorney Angela Corey said the motive for the killings was not insanity, but the desire to cover up the rape of Mrs. Smits.

''He raped her and he killed her and he killed the only other living witness that could testify against him,'' Ms. Corey said. A second child, an infant, was unharmed in the attack, but suffered dehydration before the bodies were found two days later.

Ms. Corey urged the jury to reject all other possible verdicts, which include manslaughter and second- and third-degree murder.

''It is an insult to label the murders of Paula and Amanda Smits as less than first-degree murder,'' she said.

Fellow prosecutor Jon Phillips used clay models of the victims' heads and had a woman employee dress in Mrs. Smits' nightgown to show the killings were cold-blooded.

Taylor had claimed he had consentual sex with Mrs. Smits, but Phillips showed the jury how her nightgown had been slit down the front with a knife.

Testimony indicated that Taylor planned to tie up Mrs. Smits with the nightgown, but eventually used a cord from curtains. He also put a gag in her mouth, although the defense contended there were no screams.

''If Paula Smits wasn't doing the screaming, then who was?'' said defense attorney Ann Finnell. ''The screaming was coming from Walter Taylor's mind. Walter Taylor still hears the screams.''

Finnell said that during the slayings, Taylor was under the delusion that Mrs. Smits was an Iraqi agent out to harm him.

''He's having flashbacks to the missile attacks. His dead friends are with him. He's living a nightmare,'' she said.

During the trial, prosecution witnesses sought to show Taylor was sane at the time of the killings, attempting to hide the hammer and knife used in the attack, as well as a bottle of wine he drank.

Therapists testified earlier this week that Taylor has a personality disorder stemming from an abusive and unstable upbringing and was suffering from a mental defect that caused him to lose touch with reality.