I agree with the others, check your local laws and your lease.
Personally, once they are evicted and I have possession of the property, I would store the stuff for 30 days then deem it abandoned. If after the 30 days they want the stuff back, I would tell them to pay their owed balance or I would be forced to sell their stuff as agreed in our lease. Many Pro-landlord states deem 30 days sufficient to store someones stuff before it is abandoned. If they want their stuff before the 30 days is completed, I would return it to them and when they come to get it from me I would have them served with a small claims summons to collect the unpaid rent and damages. Or after the 30 days, I would tell them to sue me for it and file a counter claim for unpaid rent, damages, and removal fees.
Before the 30 days, give the stuff back. After 30 days of possession, the ball is in your court. This is coming from my understanding of Idaho Law though. I am not a lawyer though but I would feel comfortable with this in front of a judge holding our lease agreement which they broke which spells this out. If your lease is silent about this, update it promptly!