. >> reporter: at his office outside los angeles, we asked nicolosi if he remembered treating ryan kendall about 14 years earlier. >> i'm not familiar with the name at all. >> reporter: his parents have provided bills from your office. there have been checks written to your office but no record. >> no. >> reporter: he says that your therapy was quite harmful. he said that you told him to butch up, quote, unquote. >> never. that's not our language. >> reporter: when somebody says people like yourself, others are trying to get the gay out of people. >> that's a terrible way of phrasing it. i would rather say we are trying to bring out the heterosexuality in you. >> reporter: nicolosi says he's kept hundreds of children from growing up gay. he credits this man, george reicherk, who is a researcher and big believer that homosexuality can be prevented. he worked as a doctoral student at ucla in the '70s. in a government funded experimental program later called sissy boy syndrome, he treated a boy named kirk murphy. to turn around kirk's so-called sissy behavior, kirk was repeatedly asked to cho