Travis County District Attorney Ronnie Earle has told his staff he won't seek re-election next year. He has held the office since 1976.

The 65-year-old Earle, who's been at the center of the criminal investigation of former U.S. House Majority Leader Tom DeLay, made the announcement Friday.

His term has one year remaining.

"There are particular cases pending that are enormously important to this State, this country, and democracy itself," Earle said in a statement. "If they are not resolved during the forthcoming last year of my term I will offer my assistance on those matters on a pro bono basis to my successor."

Earle said he has no specific plans after stepping down.

"I look forward to whatever the future may bring," he said. "I have no specific plans, other than to not go gently into that good night."

State Dsitrict Judge Jeanne Meurer is among those who have been mentioned as a successor for Earle. She issued a statement Friday evening:

"The people of Travis County owe Ronnie Earle an enormous debt of gratitude for his thirty years of service as our District Attorney. As a result of Ronnie's decision to leave office, I am carefully considering the opportunity to run, and to continue to serve our community. Serving as District Attorney is obviously a serious responsibility, and after thoughtful consideration, I expect to make a decision next week."

Earle, a Democrat, has come under constant criticism from DeLay and other Republicans, who say some of his prosecutions of elected leaders are politically motivated. Earle has insisted that he prosecutes Democrats as well as Republicans.

A Fort Worth native, Earle is also a former member of the Texas House of Representatives, former presiding judge of the Austin Municipal Court, and former chief counsel of the Texas Judicial Council.

Earle created the Public Integrity Unit of his office to prosecute ethics violations in Texas State government. His targets included then Texas State Treasurer Kay Bailey Hutchison for alleged misuse of state telephones. She was indicted but acquitted.

He gained national attention for filing charges against House majority leader Tom DeLay in September 2005, accusing him of possible violations of Texas campaign finance law in the 2002 state legislative election.

Ronnie Earle and his wife, Twila Hugley Earle, have been married for 27 years and are the parents of three grown children.

The Associated Press contributed to this report.