Feazell announced his candidacy for District Attorney of McLennan County in Waco, Texas in 1982. He would go on to win the election against the incumbent district attorney and became one of the youngest to hold the position in McLennan County. During his first term as District Attorney, Feazell tried the 1982 Lake Waco Triple Murders. In 1984, a jury found David Wayne Spence guilty of the murders and sentenced him to the death penalty. A chronicle of the Lake Waco Murders can be found in the Edgar Award-winning book Careless Whispers by Carlton Stowers.Feazell notes on his website that he is “now a vocal advocate against the death penalty.”
In 1984, after Henry Lee Lucas claimed to have killed over 300 people across the country, the Texas Rangers announced numerous murders to have been solved. Three of these announced murders were in McLennan County. This prompted Feazell to begin investigating the claims. This resulted in the Lucas Report. The report suggested that Lucas could not have committed some of the murders to which he had confessed. A decision afterwards resulted in Feazell’s arrest.There were nineteen agents in town for Feazell’s arrest and the search of his office and home.
Feazell’s arrest came seven weeks before election day. Voters in McLennan County re-elected Feazell for another term. During the criminal investigation leading up to Feazell’s indictment, a reporter from Dallas television station WFAA-TV named Charles Duncan ran an eleven-part series about Feazell, which later led to a libel judgement in favor of Feazell worth $58 million.This series was the only evidence shown to the federal grand jury that indicted Feazell.Feazell was found not guilty of all charges on June 29, 1987. Feazell then returned to work as District Attorney of McLennan County. On September 13, 1988, Feazell sent out a press release stating he would be resigning as District Attorney.
Feazell then began representing Lucas in all of the still-pending murder cases he had confessed to around the country. Feazell spent much of the 1990s representing Lucas to ensure he was not convicted based on any more false confessions. The work done by Feazell and others cast enough doubt on the validity of the Lucas confession to the Orange Socks murder case that in 1998 then-Governor George W. Bush commuted Lucas’s death penalty to life imprisonment.
In 1991, represented by former U.S. Attorney Gary Richardson, Feazell was awarded a $58 million judgment for libel charges against WFAA-TV, at the time the largest libel judgment in U.S. history. As a result, he was cited in the 1993 edition of Guinness World Records for largest defamation lawsuit in history.