A Libertyville attorney said alleged mishandling of DNA evidence in high-profile murder cases led him to today announce his candidacy for Lake County State’s Attorney.

Democrat Chris Kennedy, a former assistant state’s attorney, seeks to replace Michael Waller, a Republican who has held the office for more than 20 years.

“A change is in order,” Kennedy said after a press conference attended by about two dozen supporters.

He said the office is in need of a Conviction Integrity Unit to review past DNA cases and monitor procedures throughout the investigation and prosecution of serious cases.

A special unit focused on sexual offenses would also create more fairness and oversight in the State’s Attorney’s office, he said.

Kennedy said he was in part motivated to run for the office because his cousin’s 24-year-old daughter, Hillary Johnson of Chicago, was murdered in Tennessee in 1999. Her murderer was a convicted sex offender who had killed a man shortly before abducting and killing Johnson.

He said prosecutors “missed opportunities to keep this predator off the street” – something he would strive to avoid if placed in office.

A 1994 graduate of The John Marshall Law School in Chicago, Kennedy worked for four years as an Assistant State’s Attorney under Waller. He’s worked in private practice in a Lake Forest firm since 1998, saying he left the post in Waller’s office because the salary was too low.

The Bronx, N.Y. native and his wife, Lisa, have lived in Libertyville for 15 years and have three children.

Waller, who has not yet announced whether he’ll run for a sixth re-election, did not respond to a request for comment.