@stux

Sounds like a bruised ego, but you never want to underestimate violent morons. Hopefully she doesn't allow him inside....

If this asshole is violent, he may try to break into a residence.

This may be out of scope:

Security -
If your landlord doesn't throw a fit, a front door can be hardened-
* Grade 1 deadbolt
* Lock strike plate (ideally a 4-screw, with 3 inch screws to get in the studs) but make sure the frame does not need to be modified to fit the strike plate if opting for one.