Well, this is bleak.
99 Days tells the story of Los Angeles Police Detective Antoine Boyd (whose last name is "Davis" on the back cover blurb, oddly enough) and the latest case he and his partner, Valeria Torres, are working on. The body of a woman is discovered in her house, hacked up by a machete. Antoine recognizes that it's a machete because back in 1994, he was a 12-year-old Hutu in Rwanda, where he was forced to engage in the massacres of the Tutsi. The book moves back and forth between the present and 1994, as Antoine finds out that he can't really escape his past.
Casali tells the story as a fairly normal police procedural - Antoine and Valeria follow leads, interview suspects, and eventually begin to figure out the reasons behind the murders (because yes, there are more murders). The first victim, it turns out, was dating a leader of the Crips but was cheating on him with a member of the Bloods, which doesn't sound terribly smart. Neither gang member appears to be the killer, but the two gangs use the murders as an excuse to start up a long-dormant war. So Antoine and Valeria are trying to catch a serial killer while Los Angeles goes up in flames (quite literally) around them. Their boss, naturally, wants them to catch the killer quickly because he's concerned about how it looks in the media, especially because the victims are all low-income minorities. Meanwhile, Antoine is struggling with his memories and the feelings they're stirring up.
It appears he's taking medication for schizophrenia, but it's never clearly stated what's afflicting him. So nothing is really going well for him.
The story moves along well, as Casali makes sure the plot never bogs down and makes a good deal of sense (believe me, in some murder mysteries, that's a secondary consideration). The book isn't the most subtle thing in the world - the gang war between two groups of black men is linked to the massacres in Rwanda; Antoine is denigrated by a white co-worker as a "quota boy"; the big secret that Antoine is carrying around is fairly obvious. That's not necessarily a bad thing, because Casali does a really nice job with Antoine's mental state, which is the crux of the story - how can he live with the memories he has of Rwanda and still function, and what happens when a killer keeps reminding him about it? The fact that the killer uses a machete is a nice touch, too, and explained well. The book takes us into some very dark places, and it's to Casali's credit that he doesn't shrink away from dealing with the horror that Antoine feels. It's uncomfortable in places, but still gripping.
Donaldson has been doing good work for years, and in this book, he tweaks down his style just enough to fit the tone of the book without losing his unique look. His Los Angeles is a seedy place, a true city of broken dreams, and while he doesn't do quite as much with Rwanda (presumably because he didn't actually go to Africa), the scenes there don't rely on the backgrounds as much.
Donaldson brings the violence to life uncomfortably well, however. Antoine is the centerpiece of the story, naturally, and Donaldson shows his slow degradation brilliantly until, at the end, he appears to be haunting his own body. It's not a flashy book, art-wise, but Donaldson tells the story exceptionally well. You wouldn't normally associate Donaldson with a gritty crime book, but his work on 99 Days is very good.
As with most of these Vertigo Crime novels, 99 Days is a good read if you like these sorts of things but it probably won't change your mind if you don't. Casali does a good job linking the worst of societies with the (supposedly) best society and showing how little the difference is between them and how quickly people can turn into monsters, and that makes this a bit more interesting than a standard crime book. Casali does a bit more with the crime than you might expect, too, which is nice. The book looks very good, too, which is certainly a plus. I'd recommend 99 Days to people who enjoy police procedurals and psychological drama, but if you're not that kind of person, it might be a tough sell. Unless you're a fan of Donaldson, in which case this is a cool book to check out!