The leak later made its way to one of former Orange Beach Mayor Steve Russo's co-defendants.
U.S. District Judge William Steele in Mobile on Thursday sentenced Charlie McNichol to a year of probation.
Mobile County Sheriff Sam Cochran and Mobile Police Chief Phillip Garrett were among McNichol's supporters at sentencing.
"This is, as you can imagine, very embarrassing, very humiliating for me to be here before you in this capacity," McNichol told the judge.
McNichol, 42, a former Daphne police officer, resigned last month from his job with the U.S. Attorney's Office after pleading guilty to the charge - technically, theft of government property.
Assistant U.S. Attorney Randall Hensel of Pensacola, Fla., who led the prosecution, acknowledged that McNichol's friend had no connection to the Orange Beach case. But he told Steele that one of Russo's co-defendants learned of the details that McNichol had provided.
Those details included advance knowledge of a news conference that prosecutors called to announce an indictment in the Orange Beach case last year, the Press-Register reported in a story Friday.
Information from: Press-Register,