Janesville Police complete their investigation into the accidental discharged of an officer-issued firearm at Edison Middle School in September.

According to a news release, the holster and gun were sent to their respective manufacturers where inspections and tests found no defects.

At the time of the incident, the officer said that the strap to their backpack was hooked on the grip of the firearm, and that they were pulling on it when the gun went off.

Janesville Police say the only reasonable explanation is that the backpack strap tail got into the holster and engaged the trigger.

Janesville Police say it was an unintentional, unique, and isolated incident.

Nobody was hurt.