This would be the second book in the Retrieval Artists Series by Kristine Kathryn Rusch, the first was The Disappeared. For whatever reason, this one is out of print and I had to order it from a seller on Amazon. No idea what that's about since the book before and the ones after are still in print. And it's not like it was a bad book or something either! I quite enjoyed it. Lots of character development stuff happened for the main character and his former partner.
This one centers around a murder at the moon marathon and the possible involvement of a Disappeared in that and the following events. (about which I shan't go into detail so as not to ruin it for anyone who happens across this!)
I'm planning to go get number three in the series at Borders tomorrow. I'm home on vacation and I need another book!