I am a little confused, the homes on Zillow that are either in "pre foreclosure" or "foreclosure" state that they are NOT on the MLS and that they are usually bank owned. Is it a guessing game if someone is still occupying the property and who can I contact about the property?
If the home is in pre-foreclosure, the current owner is still in control of the property and would be the primary contact to moving forward with a sale. If the home is foreclosed, the bank would be the owner. Most banks have a specific process for listing the homes and its likely to be put on the market in the future.
On a side note, the data in Zillow is terrible and highly unreliable. Make sure you double check any data with the county recorder to see if anything has been actually filed. Its embarrassing (and unprofessional) to approach someone about solving their foreclosure issue when none exists and these owners won't be very kind when responding to you.
When the bank is ready to sell them they list them on the MLS with brokers as REO properties.