We have a tenant who seems to have moved out, but has left behind a couple of old couches & a microwave. Her lease ended end of Feb & she had not paid her rent since Dec though we did have her last month's rent. The problem is that we want to rerent the apt but she has not given us the keys & the electricity is still in her name. We have sent her a certified letter (to the apt) but it was returned to us saying No Forwarding Information available.
Not sure how to proceed. Can we take over the apt, change the locks etc & rerent it from next month? We can store her couches in the basement in case she comes back for them. Please advise. Thanks.

Abandoned property
Very common and very difficult situation for landlords. There is not perfect answers, but follow this link to a thread about dealing with tenant's abandoned property.