NORWALK, Conn. — A forensics expert testifying at the trial of Kennedy cousin Michael Skakel said he found no direct DNA evidence linking the defendant to the 1975 beating death of Martha Moxley.

Dr. Henry Lee, a former state commissioner of public safety, took the stand this week at Skakel's murder trial in Norwalk Superior Court.

"We did not find any other person's blood type. We did not find any foreign DNA," said Lee, who has testified in high-profile trials with such defendants as O.J. Simpson and William Kennedy Smith.

Moxley was beaten to death with a golf club on Oct. 30, 1975, when she and Skakel were 15. Skakel is a nephew of Robert F. Kennedy's widow, Ethel.

Skakel, now 41, was charged in January 2000 with Moxley's murder after a one-judge grand jury investigation.

In the courtroom on Wednesday, defense attorney Michael Sherman said there was no direct evidence that his client killed Moxley. Lee replied, "I don't have direct but I have indirect evidence."

Lee also testified that two hairs found on a sheet police used to wrap Moxley's body showed microscopically similar characteristics to hair taken from Kenneth Littleton, a tutor at the Skakel home who was an initial focus of the murder investigation. But under questioning from prosecutor Jonathan Benedict, Lee said no DNA was found in the hair and that the evaluation also showed some dissimilarities in the hair.

Also, a retired Greenwich police chief testified that he unsuccessfully sought an arrest warrant in 1976 for Skakel's older brother in Moxley's murder.

Thomas Keegan, who at the time of the killing was a captain in charge of the investigation, said he once presented an affidavit to the state's attorney's office seeking to arrest Thomas Skakel on a murder charge. Prosecutors rejected the request, saying there was not enough evidence to establish probable cause, Keegan said.

Sherman asked Keegan if he believed there was enough evidence to charge Thomas Skakel with the crime.

"You wouldn't just sign (the warrant application) willy-nilly?" Sherman asked.

"It would not be a frivolous thing," Keegan responded.

Authorities are basing their case against Michael Skakel on admissions of guilt he allegedly made years after the murder and the warrant application for his brother.

Benedict, who objected to the testimony, downplayed the warrant request. He said it simply indicated that at some point at least one police officer thought there was evidence against Thomas Skakel, who was the last person seen with Moxley.

Sherman has not been shy about trying to implicate Littleton in the murder to create reasonable doubt that Skakel committed the crime. But until now he had not focused on his client's older brother as a suspect.