Yet another detective book to discover

Found myself another detective, Alex Delaware, author Jonathan Kellerman. As usual I picked up a book at hazard, "The Murder Book", the french title is "Que elle repose en paix", not exactly the exact translation...., I will have to look for the books in this detective series in the original language. There are lot of jargon and local english word that I think aren't coming out right in french. In any case nothing is more pure than the water from the source, that's why I prefer reading books in original language when ever possible.
What I found interesting in this book is that the main protagonists are somewhat different from the usual detective image, hence : L.A. detective Boch, or Rebus the Scottish detective, both having military background and their battle with cigarettes and alcohol, plus being divorced and having a difficult (for others in the book) personality.
J. Kellerman's main characters are Alex Delaware and Milo Sturgis, former is a doctor in psychology and the latter a gay homicide police detective (yet again a military background), a combination of detective and a doctor, a base to well known Kay Scarpetta and Pete Marino, a lot of detective books now star duos as main characters. In Kellermans book there is a mild change from the lone detective going against the everyday tide, I remember even one that had a leg missing and another well known Lincoln Rhyme that was quadriplegic. There no end to the variety of detectives, it seems, the most strange one I know of was Dr. Who.
Anyway, back to Kellerman's Dr. Delaware and inspector Milo, they form a complementary duo, each one working in their own respective reality and meeting up every now and then for a chat and exchange of ideas that lead eventually to resolving the case. What I liked in "The Murder Book" was the human side of these two characters each one with their own problems, the end of the book was a disappointment a little bit quick with the bad boys killed instead of going to jail. Suddenly everything was just over, it left me a little bit perplexed since the first part of the book was nice and slow with lot's of details and convincing rendering of different caracters. J. Kellerman has written 13 books featuring Alex and Milo and I look forward to read them all and discover more about this crime killer duo.
Now there is only one question, should I read the books in chronological order or start from the most recent one and move down the line ?