This provides a perfect opportunity for Officer Suzuki, the inspector's assistant, to make use of her mathematical training. The following quote from Inspector Morimoto and the Two Umbrellas, the first book in the series, explains the connection Suzuki sees between mathematics and her work for the police department:

Although her reasoning skills are tested in each of the novels, it is here that it is most explicitly mathematical. Fortunately, "Timothy Hemion," author of the Inspector Morimoto mystery novels, is the pseudonym of statistics professor Tony Hayter, who proved the Tukey-Kramer conjecture. So, the mathematics is handled well. (See here for an article about the author on his institution's website and here for an interview with him.)

In the end, although the testimony of the expert witness is shown to be correct from a purely computational point of view, it is recognized that like most results in probability and statistics it should not be accepted naively without considering the validity of the assumptions and the direction of causality.

Thanks to Dan Flath for bringing this series of books to my attention.