automatic door locks

[Todd M.]

Hello,

I have a 4 plex with a common door with access to utility room. Tenants are suppose to keep this door locked (deadbolt and regular handle lock) at all times. Well, they don't and I had a "break in".

Thieves came in and busted off the coin boxes from washer and dryer.

I'm looking for ways/ suggestions to keep that common door locked at all times. Is there some kind of automatic door lock?

Thoughts?

Thanks in advance,
Todd