LIVINGSTON, Texas - Walter Bell stands on his bunk and stretches his nearly 6-foot frame to peer through a slit of a window high on the concrete back wall of his tiny prison cell. Asked what he likes to watch through the narrow slice of glass, Bell's slowly spoken words are flavored by the Cajun dialect of his native Louisiana, even though he's spent most of his life in Texas.

"Cars, people riding motorcycles," he says. "Planes, helicopters ... the in-and-out gate."

The gate he sees is an entrance to the Polunsky Unit of the Texas Department of Criminal Justice, home of Texas' death row. It's where Bell, 50, has served 29 years — more time than any other condemned Texas inmate — for the 1974 slayings of a Port Arthur couple. On Thursday, a court hearing is planned to determine whether Bell is mentally retarded. A Supreme Court ruling two years ago bars the execution of mentally retarded people so the hearing could mean the difference between life or death for Bell.

"The records uniformly state he has retardation," said William Christian III, who is seeking to have Bell's sentence commuted to life in prison.

School records show Bell had an IQ of 54 at age 9, 16 points below what is considered the threshold for retardation. He attended special education classes beginning in the second grade. At age 14, his IQ was 62, records show. He finished school with a special education diploma and joined the Marines, where he flunked boot camp twice and was determined to be "almost valueless," according to a commanding officer.

Bell's case is the latest in Texas to cite the Supreme Court's ruling in a case known as Atkins, named after a Virginia convict. The scheduled executions of three Texas inmates were halted this year based on the high court's decision. Last month, Texas' highest criminal court for the first time commuted a death sentence because the convict was deemed retarded.

State District Judge Charles Carver will consider evidence from Bell's hearing and send his conclusions to the Texas Court of Criminal Appeals, which will decide whether to commute, overturn or affirm Bell's death sentence.

Bell has been convicted and condemned in three trials for the murders of Ferd Chisum, an appliance dealer, and his wife, Irene.

Prosecutors contended Bell, who had been fired by Chisum, showed up at the couple's home 90 miles east of Houston under the guise of seeking help for applying to a trade school. They say Bell attacked them, raped the woman, forced her to write him checks, then strangled her with a towel. Her body was dumped in a bathtub, joining the body of her husband, who had been beaten and stabbed.

Bell was arrested the next day while shooting pool after trying to cash the checks.

In 1974, Bell was convicted of killing Irene Chisum and given the death penalty. On appeal, the sentence was commuted to life. In 1982, he was convicted of Ferd Chisum's slaying. That conviction was overturned because jurors were not allowed to consider mental retardation as a mitigating factor in his deciding his death sentence.

In 1994, he was retried and condemned for Ferd Chisum's murder. It's that death sentence that his attorneys used to return to the state courts for a mental retardation hearing, citing the Atkins case.

Rod Conerly, a prosecutor in Jefferson County, where Bell's hearing will be held, doesn't believe the Supreme Court decision applies to Bell. He contends Bell planned to kill the Chisums, assembling crime tools that included handcuffs and an extension cord to restrain them.

"The nature of the crime itself, the sophistication with which he pulled off the crime, is I think indicative of someone who is not mentally retarded," Conerly said.

Bell says he didn't kill the Chisums and a confession was forced out of him by authorities.

"I thought they were picking me up for those checks at the bank," he said, blaming friends for giving him the Chisums' stolen checks.

For all his years on death row, prison records show Bell has been a good prisoner. He's never had to be disciplined with solitary confinement. He spends much of his time in his roughly 6-by-10 cell. He has no TV, just a radio. He doesn't read or write well. Under the law when Bell first was convicted, an inmate serving life became eligible for parole after 20 years. It's unclear whether parole is a possibility for him, should his sentence get commuted.

Bell already is thinking about life outside.

"I know I'd have problems paying bills, buying clothes. It will be hard but a lot of people tell me — religious people — they'd help me out," he said, referring to prison ministers who have offered assistance. "They all understand my situation. ... I didn't ask to be like this."