DURHAM, N.C. — Prosecutor Jim Hardin Jr., a fair-haired version of Al Gore in appearance and demeanor, is hardly a Homer J. Simpson lookalike.

But one could almost hear Hardin let out a Homeric "Doh!" on Friday when a witness opened up an evidence container and found it to be empty.

That's basically how it has been going for prosecutors trying to convict novelist Michael Peterson of murdering his wife, Kathleen Peterson, 18 months ago. Hardin has no choice but to have two evidence technicians testify about items they collected from the Peterson home. But each time they do, jurors learn about more and more police blunders.

The latest gaffe came Friday when Hardin was trying to introduce into evidence a small piece of metal discovered on the 15th step down from the top of the staircase on which Kathleen Peterson's body was found.

On Friday, David Rudolf defended his right to speak to the media.

Hardin proceeded by the book. The prosecutor got evidence technician Eric Campen to first identify a paper bag that contained an evidence container in which the evidence was stored. Then he got Campen to identify the container.

But when the container was finally opened, the piece of metal Hardin expected Campen to find inside wasn't there.

The evidence was likely misplaced during testing, but the incident is a good example of problems the prosecution has encountered. There have been others.

Campen, for instance, testified that police tested a wine bottle for the presence of blood. The test, however, made it impossible for police to dust the bottle for fingerprints, something that should have been done first.

Defense lawyer David Rudolf has not missed an opportunity to underscore police errors. The defense hopes that if jurors have no confidence in the integrity of the evidence police seized, they will also have no confidence in the conclusions prosecution experts have yet to testify about.

Rudolf broached the subject of the missing metal within minutes of starting his cross-examination of Campen. The defense lawyer asked the witness if he remembered testifying that he opened the container and it was empty.

"There were a couple of small, tiny specks in there, but not the metal item I placed in there," Campen said.

"Do you know where it is?" Rudolf shot back.

"No, I don't know," Campen answered.

"Do you know why it wasn't in there?" Rudolf continued, asking the same question a different way.

"No, I don't," Campen said.

When court ended Friday, Hardin complained to Judge Orlando Hudson Jr. about an appearance Rudolf made Thursday night on Court TV's Crier Live program. Rudolf talked to host Catherine Crier about blood spatter evidence that hasn't been presented to jurors yet and the subject of his client's sexual preferences.

"It could be influencing potential witnesses," Hardin argued to the judge.

Hudson said he is not that concerned about comments being made out of court by the lawyers now that a jury has been picked and the panel members have taken an oath not to watch television or read newspaper accounts about the trial.

"Once this jury got picked, I think I got control of the jury and the only way they could get this information is through dishonesty or if someone inadvertently gave it to them," Hudson said. He added later, "I'm reluctant to order lawyers not to talk once we got the jury picked."

Rudolf said he felt it was important to go on the program to counter prosecution leaks to the local media about Peterson's alleged sexual preference. (The reports were that Peterson may be bisexual, but Rudolf didn't address the issue in detail.)

"All I said was that Mr. Peterson's sexuality has nothing to do with this case," Rudolf said. "If anyone is trying to influence anyone, it's the people who are leaking that information."

The fifth week of the trial, which began July 1, begins Monday at 9:30am. The trial is being broadcast by Court TV.