Bill James 
The Lolita Man [EPUB ebook] 

The second title in the popular Harpur and Iles series. Five teenage girls have been raped and murdered, and the criminal is still at large. Detective Chief Superintendent Colin Harpur, assigned to the case, is a tough hunter, but so is the 'Lolita man’ watching the school playgrounds. Now it looks as if the daughter of Harpur’s friend may be the latest victim. Virtually obsessed with the urgency of the matter, and hampered by the bitter police rivalry that is jeopardising the case, Harpur decides to go it alone.