This one of Kellerman's series featuring psychoanalyst Alex Delaware. I've read a few of the others and I like the character.
Alex is asked to provide an expert opinion about a young woman named Cherie, whose sister, Connie, is suing for custody of Cherie's child and accusing Cherie of being an incompetent mother. Alex visits Cherie's home and finds nothing to indicate that she is a bad mother. The child appears to be happy and healthy.
When Connie loses the case because of Alex's testimony, she vows to keep fighting, and says she will never give up until she has the child.
Then someone murders her.
And Cherie checks out of her apartment without giving notice.
Concerned that his professional opinion about Cherie may have been totally wrong, Alex works with his friend, Detective Milo Sturgis, to hunt her down and uncover the truth.
If you like suspense thrillers, you will enjoy this one, but I think the reason it has a fairly low rating (for a best selling author) is that I was able to guess who the real killer was before he revealed it.