An Adams Township man who made up fake identities to victimize teenaged girls he befriended on Facebook will spend 14 to 28 years in prison.

William Ainsworth, 55, pretended to be teenaged boys to garner the trust of more than 600 unsuspecting teens in Beaver, Butler and Allegheny counties. Once those teens added Ainsworth’s personas to their “friends” list, he preyed on the vulnerable, convincing girls to share their secrets, open their trust and send him naked photographs.

Two of the girls agreed to meet Ainsworth. One of them had sex with him.

He was sentenced Monday by Butler County Judge Tim McCune.

Ainsworth, who pleaded guilty to more than 75 crimes including involuntary deviate sexual intercourse and solicitation of unlawful contact with a minor, said the 2011 deceit “started out as an innocent act.”

Ainsworth claims he first went on Facebook with a completely different intention: To monitor the activities of his own twin teenaged girls and be sure they were not getting involved with shady characters.

But while on the Internet, Ainsworth, who has a white beard and thinning hair, pretended to be a young surfer from Florida and a rebellious high school drop out

Court records allege Ainsworth concocted an “elaborate and disturbing” tale of the fictitious identities, intertwining the persona’s lives, using photographs from other places to bolster his claims. At one point, he announced the death of one of the personas.

Once in the teen’s confidence, Ainsworth’s personalities allegedly would compliment the victims, and discuss their problems at school and at home.

In the process, he convinced five of the girls to share naked photographs of themselves with him. Two of the girls were convinced to meet with Ainsworth.