Memory in Death by J.D. Robb
It's almost Christmas time and Lieutenant Eve Dallas gets called out to a Santa that's fallen from a building and crushed a pedestrian below him. While looking in to the illegals Santa was on, Eve comes back to her office to find Trudy Lombard, a woman who fostered her for a short time as a kid. It hits Eve like a tonne of bricks because there aren't fond memories. Eve tells Trudy to get out and goes home to tell her husband Roarke of what has happened. Not surprisingly, Roarke finds Trudy in his office the next day, trying to blackmail $2M from him to keep his wife's past from the media. Roarke doesn't buy it, threatens her, and she leaves. A few days later, Eve decides that she needs to meet Trudy herself and tell her to never contact them again. What she finds is that Trudy is dead, her head bashed in.
This was a fairly unique book in the In Death series in that the murder that Eve is trying to solve doesn't happen until about 100 pages in. We learn a lot more about her past in this book and how tough things were for her. I also liked watching Eve and Roarke during the holidays.
First Line: "Death was not taking a holiday"