I believe this is the first mass murder we have seen Banks tackle; and Robinson doesn't spare us in the first chapter with his description of the members of a wedding party falling victim to a sniper.
Banks and his author become more and more aware of the complicated relationship between the media and law enforcement as both get older. In fact, the most annoying chapters for both Banks and this reader are those where he clashes with Adrian, the media officer for the police. The progress of this novel, however, depends largely on a discussion of whether they (and the public) will be satisfied by the apparent solution they have reached halfway through, even though they lack understanding of the motivations of the (apparent) murderer who has (apparently) suicided after his crimes, in the common pattern. It's no great spoiler, given that there are 200 pages still to go in the the novel, that the initial explanation doesn't suffice for anybody.
I was not particularly thrilled about the reintroduction of psychologist Jenny Fuller as a likely romantic interest for Banks (again), but at least she's more age-appropriate than recent candidates, and they're both being extremely cautious.
I continue to enjoy the supporting cast of women police officers - Annie Cabbot and Gerry Masterson - who at this point in the series are nearly as primary to each investigation as Banks. (Winsome Jackson is sidelined with a flesh wound inflicted by the sniper in this story; a pity.)
There are readers who are tiring of the Banks series after so many entries (this is #24, and there is another one out already). I am not one of those readers.