When Adult Children Move Out of Your Home

My question involves criminal law for the state of: Ohio

What is the law involving adult children who move out of your home and leave possessions? How long do they have the right to enter your home without your permission or without you being home? How does the law determine who owns what? If an adult child moves out, leaves a note notifying you that they have moved out, advised you in person when you contact them....that they no longer wish to have contact with you and that they will not be returning......do they have a right to enter your home at any time because they have a key? Or come through a window? How can you legally notify them that it will be considered trespassing if they enter your property? These adult children managed to remove quite a few things that did not belong to them....and left quite a few things that did. Our local sheriff advises that they have the right to enter the home because they lived their previously. There has to be a limit on this.
Thanks for your help in advance!

When Adult Children Move Out of Your Home