Officials broke ground Friday on a memorial that will pay a lasting tribute to a Mount Vernon police officer who was fatally shot in a case of mistaken identity.

Officer Christopher Ridley, 23, was attempting to break up a fight 11 years ago when he was shot and killed by Westchester County police outside the County District Building.

Months later, county officers told a federal grand jury that they had no idea that Ridley, in plain clothes, was a cop. All four officers were found not liable for his death.

Last year, the county approved to contribute $150,000 to the $350,000 memorial, which has yet to be designed. It will stand at 85 Court St. in White Plains.

Ridley's family, who will play a part in helping to design the memorial, say it will represent a part of the officer and who he really was.

County officials say they hope to have the memorial completed by this time next year.