The Killing Mood (DCI Andy Gilchrist, Bk. 12)

Mid-winter, St. Andrews, Scotland: When a university lecturer fails to turn up for class, he is found dead at home, with evidence of having committed suicide. A female student reports to the police that she was having an affair with him and knows he would never commit suicide. Toxicology results turn up Class A drugs in his system, and DCI Andy Gilchrist and his associate, DS Jessie Janes, are called in to investigate.  

The initial enquiry soon turns into a murder investigation, and when Gilchrist and Jessie dig deep into the man's background they uncover a criminal past, a history of romance scams, and several bank accounts containing hundreds of thousands of pounds. A forensic search of the man's computer hard-drives reveal a lengthy trail of heartbroken women tricked into parting with their savings in a futile search for love. 

Did one of those scorned women seek revenge and kill him? Or did his criminal past finally catch up with him?