According to court documents, the three were arrested after a youth advocacy group notified police of an advertisement on a personals website featuring seemly underage girls in suggestive poses with the wording "We Can Give You What U Need !! $50 Dollar Sunday Special."
Undercover officers called the number on the ads and met with Scott, also known as "Ebony." She allegedly identified Alston as her "pimp" and said Clemons took the photos.
The 17-year-old girl in the photos was located in October. She allegedly told detectives Alston was her "pimp" and if she disobeyed him, "he would put his hands" on her.
Alston was sentenced to 18 to 60 months in prison and 10 years of probation; Scott received up to two years in prison and five years' probation. Clemons was sentenced to three to 23 months in prison with four years' probation.
The state law that prohibits human trafficking was adopted in 2007.
"We have only begun to investigate these cases, but we have learned from other jurisdictions that these victims are out there in significant numbers," Delaware County Deputy District Attorney Michael Galantino said.
Contact staff writer Mari A. Schaefer at 610-892-9149, mschaefer@phillynews.com or @MariSchaefer on Twitter.