In what looks like a not-to-be missed 20/20 Special with Brian Ross, we get a behind the scenes look at the “hundreds or more” secret, hidden facilities that call themselves “gay conversion” camps. In one extraordinary showdown, investigative reporter Brian Ross confronts Christian Pastor William Knott, who ran an unlicensed gay conversion center in Alabama. Things quickly escalated.

“I’m with ABC News, what did you do with those boys?” Brian Ross questioned.

“I don’t want to talk to you … I told you that because I don’t like you, get away from me,” Knott screamed.

“Is this how you treat the young boys?” Ross asked.

“This is how I treat you, get away from me,” Knott yelled back.

Knott, along with two other owners of the Alabama camp called Saving Youth Foundation, was convicted on multiple charges of aggravated child abuse. According to a local report, police found dozens of children locked in isolation chambers and forced to wear shackles.  Six teens agreed to testify during the trial, and last month Knott was sentenced to 20 years in prison.

“For every camp like this there are a 100 more that nobody knows about that nobody is exposing on T.V.,” said Susan Cottrell, from FreeHearts, an advocacy group.

The 20/20 special is expected to air on Friday night.