PHILADELPHIA (WPVI) --Philadelphia's embattled district attorney is facing a challenger.
A former co-worker announced Thursday he'll run in the Democratic Primary against Seth Williams.
Joe Khan says Williams' integrity has been compromised because of financial missteps.
Khan, with 16 years under his belt as a Philadelphia assistant district attorney and, until two weeks ago, a federal prosecutor, is the first Democrat to announce a challenge to the incumbent that will come in the May primary.
Khan, once a colleague of Williams, says he has made a mess of the office during his two terms and has got to go.
"I know Seth Williams. He has lost his way. He has mismanaged a great office. I am ready to restore integrity, judgement and fairness to the District Attorney's Office," said Khan.
Williams' integrity has been called into question as federal investigators probe his personal and political finances.
Though he has not been charged with any crimes, his campaign chairman released a brief response to the Khan announcement Thursday, saying he has been a reformer.
"He looks forward to discussing his record and agenda for a third term with whoever decides to run," Daniel Fee, Williams' campaign spokesman, said in a statement.