Clearane from a Municipal Police Department

Due to the recent audit by FBI, my City Police will require me to complete Security Clearance Questionnaire. They just need to provide some sort of proof to FBI that they have checked the City employees even though I’m not a Police civilian employee, but I have access to Police data so I’m asked to answer the questions of which one is “Have you EVER been questioned by any law enforcement agency as a suspect in any crime?”

More than 20 years, I was investigated by FBI for repeatedly mailing a person of opposite gender for having a crush, and that person sought help from FBI. I complied with FBI’s order to stop mailing the person, and FBI closed the case without arresting me or taking me to court or charging me. This incident did not bar me from passing any criminal background investigation since then for my employment reason.

Is this something I now need to disclose to my City Police department? It will be the City Police who will be checking my answer, not FBI, but I’m certain City Police will have access to FBI data. Your opinion?

Just answer the questions truthfully, an incident that happened 20 years ago will not be a concern if no similar conduct has occurred more recently.