How can I find out if lien holders were served at the time of forclosure?

The 1st lien holder is not going to feel very secure knowing that you are borrowing all of the down payment and closing costs. 

@Neal Weinstein if you transfer title, the title company should notify all lien holders.

In addition to the other advice you received, be especially cautious with Section 8 - if you have a lease in place and take a Sec 8 voucher holder, often you are locked in to charging them only their tenant portion as stated on the HCV contract, not any additional RENT on your lease agreement.

The second deed of trust holder that was foreclosing called me and asked if I would be interested in purchasing.

The lease holder may require the individual purchases a gun safe.

You can buy shower curtain liners for a lifetime for less than $850 ;)PS....we got a great shower curtain rod on amazon that also doubles as a towel holder. 

File the eviction for the lease holders and "any unknown occupants".

For those doing lease-options, beware that judgments must be paid prior to that buyer obtaining an equitable interest as a lien holder may have the right to encumber their assets, including that contract.....that may become know by filings, so pay attention.

She could sell you the house for $1 but the title remains with the mortgage holder same as a lien holder on a car.