I would suggest you also speak to local law enforcement agencies - particularly their personnel that conduct backgrounds, or administrators that make hiring decisions. Quite frankly, few college advisors are going to have any real idea of the considerations in the hiring process unless they also have a law enforcement background of some kind.
In general, your arrest and diversion should not be a statutory bar to employment in law enforcement. But, as you have been advised, the arrest and the circumstances behind it will have to be related to your potential employer and the circumstances of your arrest may give any agency pause. I say this not because it WILL happen, but it might. Some agencies may find particular backgrounds to be non-starters for reasons too numerous to adequately explain here, while others may have no problem with it at all. Generally, the more time and good works that have gone between the event and the application, the better off you'll be. A rule of thumb tends to be 5 years between the incident and application.