WASHINGTON - The FBI searched the residence of the son of a Tennessee state legislator on the weekend looking for evidence linking the young man to the hacking of Republican vice-presidential candidate Sarah Palin's personal email account, two law enforcement officials told The Associated Press on Monday.

David Kernell, 20, has not returned repeated phone calls or emails from The AP since last week.

He is the son of state Representative Mike Kernell, a Memphis Democrat and chairman of Tennessee's house government operations committee. The father declined last week to discuss the possibility his son might be involved in the case.

"I had nothing to do with it, I had no knowledge or anything," Mike Kernell told The AP.

A hacker last week broke into one of the Yahoo Inc. email accounts that Palin uses, revealing as evidence a few inconsequential personal messages she has received since John McCain selected her as his running mate.

The McCain campaign confirmed the break-in and called it a "shocking invasion of the governor's privacy and a violation of law."

Palin used "gov.sarah" in one of her Yahoo email addresses she sometimes uses to conduct state business. The hacker targeted her separate "gov.palin" account.

After the break-in, a person claiming responsibility published a detailed chronology of the hacking on the website where the break-in was first disclosed. That person identified his email address as one that has been linked publicly to David Kernell.

Experts said the hacker apparently left an easy trail for investigators.

"He might as well have taken a picture of his house and uploaded it," said Ken Pfeil, an Internet security expert.

The hacker described guessing correctly that Alaska's governor had met her husband in high school, and knew Palin's date of birth and home Zip code. Using those details, the hacker tricked Yahoo's service into assigning a new password, "popcorn," for Palin's e-mail account. What started as a prank was cut short because of panic over the possibility the FBI might investigate, the hacker wrote.

The FBI and Secret Service are now investigating.

The law enforcement officials confirming the search spoke on condition of anonymity because of the sensitivity of the investigation.

In Washington, Justice Department spokeswoman Laura Sweeney would confirm only that the FBI conducted "investigative activity" late Saturday and early Sunday in Knoxville related to the case.

David Kernell is an economics major at the University of Tennessee there.