Invisible Prey (Lucas Davenport, #17)

In the richest neighbourhood of Minneapolis, two elderly women lie murdered in their home, killed with a pipe, the rooms ransacked, only small items stolen. It's clearly a random break-in by someone looking for money to buy drugs. But as he looks more closely, Davenport begins to wonder if the items are actually so small or the victims so random, if there might not be some invisible agenda at work here. Gradually, a pattern begins to emerge — and it will lead Davenport to somewhere he never expected. Which is too bad, because the killers — and yes, there is more than one of them — the killers are expecting him.