'Sadistic' UK academic sentenced to 32 years in prison for pedophilia

Matthew Falder, 29, admitted to 137 separate offenses that when put together told "a tale of ever-increasing depravity," Judge Philip Parker said according to Britain's Press Association (PA).

"Your behavior was cunning, persistent, manipulative and cruel," Parker said at Falder's sentencing in Birmingham, the United Kingdom, Monday.

Falder was accused of tricking young adults and teenagers into sending him naked pictures online, which he then used to blackmail them, according to the UK's National Crime Agency (NCA). By the time he was arrested, Falder had approached more than 300 people across the world. Forty-five victims were represented on the court indictment.

Prosecutors described Falder as a man living double life; a Cambridge University graduate and Birmingham University researcher in geophysics by day and a sexual predator by night.

"In more than 30 years of law enforcement I've never come across an offender whose sole motivation was to inflict such profound anguish and pain. Matthew Falder reveled in it," said Matt Sutton, a senior investigating officer at the NCA.

It took more than three years to track Felder down, according to Britain's Press Association. He used around 70 online identities, the PA reported.

Felder was arrested in June 2017 with the help of authorities in the United States, Australia and Europe.