The new tenant called this morning, before I was in the office. He was very polite.

"Don't you change locks on apartments?"

"Always."

"Well, last night the old tenant came waltzing into the apartment using the key."

"I don't see how that is possible. I need to contact maintenance. I'll get back to you this morning."

So, I called the maintenance person. "Yes I did change those locks, and I don't believe they are telling you the truth."

It happens that today is payday, and paperwork was due in last Friday. So, when I got to the office, I pulled the workorder. He had marked that he changed the locks.

So, I called the tenant back. "My guy insists he changed the locks, and his paperwork says he did. I have not known him to lie to me, but..."

The tenant cut me off; "I spoke to my wife again. I am out of town on business, and she was home last night. She had told me that. I called her back, and now she says that she heard something at the door and opened it. The old tenant was there, key in hand. The old tenant said she was coming back to get some stuff that she had left, but evidently she did not actually come into the apartment. She was apparently trying the key to see if it worked."

I told the tenant to call the police, and I gave him the names of the old tenants, and their current address. I also made a note in their file about it and we will report it in the future to anyone who asks. This is a very upscale property in a very nice neighborhood. I am quite surprised by this; I wouldn't have picked these people to try something like that. But then, you never know.

The moral of the story is this: ALWAYS ALWAYS ALWAYS change locks. And keep good records. If you use these people as your source for locksets, then you can change locks - on the spot - in front of the tenant, and they'll know for certain that you have done so.

About the Author: Jim Locker is a technical guy who has done a lot of real estate investing and landlording. The experiences he writes about and advice he gives are either first hand, or in answer to specific questions posed by others. He is commonly known as jiml8 around the internet.