I rated this as 4 star rather than 5 solely on the comparison to Songer's first novel. It continues some great characters (Meg Gillis, Joe Reilly, her slightly flaky partner, etc.). The development of the primary characters is good; they grow, and along logical, explained lines. My one caveat links plot w/ character development, though.
The plot evolution (no spoilers follow) depends on the relationship between Meg's partner and another person who never appears directly in the narrative. This is probably accurate police work, but it makes for slightly puzzling reading. This missing character's role is pivotal to solving the mystery. (And would have provided a nice opening to develop the primary character, too.) Again, this probably accurate for real life police work.
Meg also spends a fair amount of time running down answers that others (hint: her hunky cop Joe) find easily through official channels. I found this both funny, ironic and pointed. A big part of Meg is her conflict over NOT being a cop anymore. For me, it emphasized both her isolation and ingenuity, working around obstacles her old badge would have levelled quickly.
All this is just explication. Songer only rates a 4 compared to her own boffo 5 debut. Compared to 95% of the perky/forumulaic/yadda yadda competition, this is still a solid hit. Betcha once the self-fulfilling 2nd book curse nerves wear off, she'll turn out to be one of the stars. Good damned read. Check it out.