Neighbor disputing property line

[CJ M.]

So I had a tenant recently move out of a duplex. There is no garage or driveway here. Tenants either park on the street in the front, or in the back yard off a small access street. The tenant shared that the nextdoor neighbor was yelling at her one day for parking on his property. She said she was parked directly behind my duplex in the dirt/gravel area that is on my property.

Anyway, I went to the unit to drop some supplies off, and sure enough, the neighbors car is parked directly behind my property in the back.

Before I "try" to have a civil discussion with the neighbor (this is a D+ neighborhood so I don't know how civil this guy will be), I wanted to get some recommendations. So far I printed the map from the auditor site that clearly shows the area in question is part of my parcel. What if the neighbor refuses to move? Is it as simple as calling the police?