A man who became infamous for kidnapping a 7-year-old boy 30 years ago is on trial again, this time for allegedly trying to buy a little boy.

Kenneth Parnell (search) is now 72, bald and in a wheelchair. But prosecutor Tim Wellman said Parnell hasn't changed since the days when he abducted Steven Stayner (search), changed the boy's name and kept him for seven years.

Stayner's story was later told in a book and TV movie, "I Know My First Name is Steven."

"There is a child predator in the courtroom," Wellman told jurors.

Parnell was arrested in January 2003 after a woman, Diane Stevens, went to police and said he tried to persuade her to bring him a young boy for $500. He was charged with solicitation to commit a crime, trying to buy a human being and attempted child-stealing.

Defense attorney Deborah Levy painted her client as an aging man who sought to take in an abandoned child. She urged jurors not to presume him guilty because of his past crimes.

Stevens knew Parnell through one of her brothers, now dead. She testified Monday that Parnell called her in December 2002 with a request for a child. "I was shocked," she said. "I think all I said was, 'A boy? A boy!"'

Stevens said Parnell asked for an English-speaking black boy, between ages 4 and 6, and said he would need a birth certificate to enroll the child in school.

Stevens also said Parnell, using a more graphic term, requested that the child have a clean bottom. In his opening statement, Wellman said the request indicates Parnell was interested in something more than simply raising a child.

"This suggests a more lurid and lustful purpose for the defendant to obtain a helpless 4-year-old," the prosecutor said.

Levy told jurors there is an innocent explanation for the request — "that he wanted a child who was clean."

Stevens cooperated with police in making tape recordings of Parnell and setting up the pretend "delivery" of a child, which led to Parnell's arrest.

Alameda County (search) Superior Court Judge Julie Conger ruled earlier that jurors could be told about the Stayner kidnapping in 1972.

After that abduction, Parnell changed Stayner's name to Dennis Parnell and told him his parents couldn't afford to keep him. But in 1980, after Parnell took a second, 5-year-old boy, Stayner got away with the youngster.

By then 14, Stayner walked into a police station with the 5-year-old and told police he didn't want the younger child to go through what he had.

Stayner testified that Parnell sexually abused him, but charges of child abuse were dismissed in 1981 when a state appeals court said the statute of limitations had expired.

Parnell served five years for kidnapping before being paroled.

Stayner was killed in a motorcycle crash in 1989. His brother, Cary Stayner, was sentenced to death last year for the murders of four women at Yosemite National Park in 1999.