I've been researching potential properties to turn into my first rental property. In so doing, I think I've located a SFH that an out of state investor purchased and started to rehab but maybe ran out of money before it was complete.

My question is, in my research I think I found the sellers number.  Is it appropriate to call the seller and try to get information/details/pain points directly from him, or go through the standard channel of the listing realtor?

Thanks for your help!

You have nothing to lose by calling him directly. If he is interested in selling the property then the thought of not using any agents may even entice him because it would save him money that he would otherwise spend on a listing agent.

If it is already listed, call the agent.