Punta Gorda, FL (Learfield Wire Services/TTWN Media Networks) - A jury in Florida has cleared a police chief of criminal negligence in connection with the death of Austin native Mary Knowlton.

The 73-year-old retired librarian was participating in a citizens academy offered by the Punta Gorda Police Department last year when she was shot to death by Officer Lee Coel during a “shoot, don’t shoot” exercise. The officer’s gun was supposed to be loaded with blanks, but was instead loaded with real bullets.

Punta Gorda Police Chief Tom Lewis was charged with culpable negligence in the case, but a jury found him not guilty at the end of a four-day trial this week.

Officer Coel is still facing a manslaughter charge and is scheduled to stand trial next year.