There are many, many studies showing the same thing. This study is just one example. See, e.g., meta-analyses of your choice:

http://psycnet.apa.org/journals/apl/79/4/599/

They're predictive, but not very.

Structured interviews are better, but not really by much.

The problem with all of these things is they work, but not very well, and people make too much of any one thing. An interview is a very small slice of behavior, even if it's structured very well.

People make too much of them.