Halloween night, the renter of a house turns off all inside & outside lights & then leaves for work at 6pm. Later that night pissed-off neighborhood trick'or'treaters eggs, breaks windows,spray-paints the house's facade because they cant get candy there (kids are out of control these days... in my day we would just move on if a house looked vacant on halloween).

ok now... WHO is supposed to pay to have the damages repaired? The renter or the landlord?

Had a sort of similar situation come up but it was burglary, not vandalism. A ring (eventually caught) was operating with two adult supervisors directing teens over nextel's during break-ins. They hit a house of ours, broke into the garage. Did some hefty damage to service door getting in and stole many of tenants tools, mower and other personal items in garage. We replaced the door (part of structure) at our own expense because it was lower than our deductible so our Dwelling Ins would not have covered it. (We keep a very high deductible and don't turn in every little claim because of the high cancellation rate in recent years). But tenant's Renters Insurance covered loss of their personal belongings ($ thousands) and if they didn't carry it they would have been out of luck.

It's just what comes from actually owning the property. The tenant is only responsible for repairs caused by HIS NEGLIGENCE. (If he had decorated for Halloween and left the porch light on, maybe you could argue he was negligent by sending the wrong signals, but still...it's not like he egged the house himself)

Just as if a burglar damages the house, it's the landlord's problem.