PHOENIX — An Arizona judge has sentenced a man to 170 years in prison in a child pornography case that he said was the darkest he had ever seen.

Sixty-one-year-old Christopher Robert Youngs was sentenced in Maricopa County Superior Court after being found guilty in April of 10 felony counts of sexual exploitation of a minor.

Authorities say Youngs, a dual citizen of England and New Zealand, in 2008 rented a moving truck and traveled throughout the Midwest before going to Arizona.

During the trip, prosecutors say Youngs chatted online with an undercover detective, saying he planned to have sex with underage girls and talked about previous encounters involving “violent sexual acts.”

Tempe police searching his hotel room found blood smears, a computer and flash drive loaded with hundreds of child pornography images and video, and a list of names of minors he planned to meet.