NORMAN, Okla. (AP) _ A prosecutor today urged jurors to condemn a man to death for killing an Oklahoma woman during a crime spree that began in Ohio and ended with his arrest while dozing in a New Mexico culvert.

A Cleveland County jury on Monday convicted Lewis Eugene Gilbert, 24, in the September 1994 shooting of Roxxy Ruddell, a 37-year-old marina security guard who had been fishing on her day off.

As the sentencing phase of Gilbert's trial got under way today, District Attorney Tim Kuykendall argued that Gilbert should die because he would pose a continuing threat to society and because there were aggravating circumstances in the murder.

Defense attorney Mark Barrett told the jury that his client was the product of extreme poverty and physical and sexual abuse as a child.

``We will ask you to seriously consider Lewis Gilbert as a person, Lewis Gilbert's life, and take that into account when you decide what must be done,'' Barrett said.

In Oklahoma, jurors' word on sentencing is not final, but judges usually follow their recommendation. The jury could choose a death sentence, life in prison without parole or life in prison.

Eric Elliott, 17, is also charged in the slaying but his trial has been postponed until January. Both Gilbert and Elliott are from Newcomerstown, Ohio.

They are also suspected in the disappearance of Ruth Loader from the Newcomerstown area and the deaths of Flossie and William Brewer of Kingdom City, Mo.

Mrs. Loader's car was found in Kingdom City and the Brewers' car was found in Oklahoma. Ms. Ruddell's truck was found near the New Mexico ditch where Gilbert and Elliott were arrested as they slept.

Kuykendall told jurors Ms. Ruddell was killed to help Gilbert avoid prosecution for the slayings of Mrs. Loader and the Brewers, adding, ``Each of the murders was accomplished in cold blood.''

Gilbert showed no emotion while the verdict was read Monday, shaking his head and saying nothing when asked about it as he left the courtroom.

During the trial, agent Daniel Becker testified Gilbert confessed to the murder of Ms. Ruddell.

The jury also listened to a tape recording in which a depressed Gilbert rambled about his fate and declined to answer specific questions.

``You wouldn't understand,'' Gilbert says on the tape. ``We did this out of craziness; you wouldn't understand it.''

Mrs. Loader remains missing.

``For me, it will never be all over with,'' her son, Tom Loader, said Monday. ``I guess the next step is to give him his sentence and then go to Missouri and do the whole thing over again and then back to Ohio.''