SANTA MARIA, Calif. – In a stinging setback for Michael Jackson, a judge ruled yesterday that the jury can hear allegations that the pop star molested or had designs on five other boys, including actor Macaulay Culkin and two youngsters who reached multimillion-dollar settlements with the singer.

District Attorney Tom Sneddon said Mr. Jackson’s inappropriate activities with these boys included kissing, hugging, and inserting his hands into their pants. He also said there was a pattern of “grooming,” or preparing the boys for molestation, but did not elaborate.

The incidents allegedly occurred 12 to 15 years ago, and the prosecutor acknowledged that only one of the five boys has agreed to testify at Mr. Jackson’s molestation trial. All other testimony would come from third parties, including the mothers of the two boys who won settlements.

Mr. Jackson, 46, is on trial on charges he molested one boy – then 13 – at his Neverland ranch in 2003.

In most criminal cases, evidence of past behavior is not admissible against a defendant. However, the California Legislature changed that in 1995, specifically in cases of child molestation and domestic violence.

Mr. Sneddon said the testimony about the five cases will show that Mr. Jackson has a consistent pattern of abuse.

Defense attorney Thomas Mesereau Jr. asked Judge Rodney Melville to exclude the allegations, saying they were based on third parties, many of whom were after Mr. Jackson’s money. The reference was to former Jackson employees who sued the singer in the past and lost, and were then ordered to pay the singer $1 million in damages.

And Mr. Mesereau said Mr. Culkin, a frequent visitor to Mr. Jackson’s Neverland ranch, “has repeatedly said he was never molested.”

Mr. Mesereau told the judge that the defense would put on a “minitrial” on each allegation that is allowed in. “You can’t stop the defense from putting on a full-blown defense and I mean just that,” the defense attorney warned.

Mr. Jackson was not present during the arguments but arrived later to cheers from fans.

The ruling came in a hearing before resumption of testimony in which comic George Lopez told about helping Mr. Jackson’s current accuser as the boy battled cancer. The comedian said he came to believe the boy’s father was more interested in money than helping his son. Mr. Lopez said the father accused the comedian of stealing $300 from the boy’s wallet.