Dead as a Doornail
In this Sookie Stackhouse novel someone is going around and shooting people. The ones that are shot are shifters, and this includes Sam. Jason comes under suspicion by the were community, since he has recently become one of them, shifting into a panther.
There's also the rivalry, basically, between Eric and Bill for Sookie's attentions, and Eric finally finds out that he and Sookie had a rather wild time together when he had lost his memory. Sookie also has to attend a werewolf battle for supremacy which is vicious and final.
Things take a turn for the worse when someone tries to kill Sookie twice, failing both times, of course.
This is another excellent novel in the series, this one concentrating on the werewolf social structure and how they do things. Each novel is fascinating in its own right, as is this one.