Looking for some basic info on foreclosure listings.

[John Spina jr]

Hello, I've been searching in my area on propertyshark.com (does anyone recommend this site?)

One listing has the following information: (I didn't include date of auction)

-1,488 SF 2 story building. $22,856 assessed value. Lien is $619,893. 

Based on this information, how does and investor know if this is a good deal or not? 

Does the investor have to buy the property for the lien amount? What does the assessed value mean and how does that effect the investor?