简单回答一下，

在市场上for sale 的房子，Title不一定是clean 的， 尤其是short sale;即便是regular sale, 也可能会有lien. 对于title上的lien, 你要查 preliminary report. 可以从任何一家Title 或Escrow Company 去order。一般正常买卖，包括regular sale\ short sale\ REO , 卖家会order并提供给买家。但 Auction要买家自己调查清楚。

任何房地产交易， 最好买title insurance, 你这种情况肯定是买家付费， 大约1000多刀。

下面是Google来的， 对sheriff sale 解释的比较清楚，

For Sheriff sale,there are a number of disadvantages to also consider prior to bidding at any sheriff sale:

1. A buyer has to conduct his or her own title search and confirm details on the real estate being considered prior to bidding at the public auction. This can very well represent lost time and money, if the buyer does not win the bid.

2. A buyer will in most cases have to buy a property being auctioned without prior inspection and in "as is" condition.

3. If a property happen to be occupied by a tenant or previous owner, it is the responsibility of a buyer to remove the occupant.