Murder Most Immoral — Anthony Hulse

After a series of murders of gynaecologists, CID suspects enigmatic triplets, Spencer, Bruce, and William Costello. DS Amy Hornby becomes romantically involved with Spencer, but inwardly suspects he may be a serial killer. Her estranged father, a notorious London crime lord complicates matters by becoming embroiled in a personal vendetta against the brothers.
This psychological thriller journeys to London, Gambia, Mauritius, Algarve, the Caribbean, and Mexico, before a thrilling finale in Scotland.
Frightening, absorbing, complex, and a guaranteed page-turner, this book will remain with you long after you have read it.