PART 1: The 1989 television miniseries I Know My First Name Is Steven is a dramatization of the real-life kidnapping of Steven Stayner, who was held captive for seven years before heroically escaping and rescuing another child.

The film chronicles the abduction of seven-year-old Steven by Kenneth Parnell in 1972. Parnell brainwashes Steven into believing his parents no longer want him and renames him "Dennis Parnell". Over the next seven years, Steven endures severe physical and sexual abuse while living a transient life with his captor. 

The story reaches its climax in 1980 when Parnell kidnaps five-year-old Timmy White. Determined to spare the young boy from the same fate, a 14-year-old Steven escapes with Timothy and brings him to a police station. The title comes from Steven's actual police statement: "I know my first name is Steven." 

Sources:
Captive Audience: A Real American Horror Story 
I Know My First Name Is Steven by Mike Echols
I Know My First Name Is Steven the movie 
https://www.theguardian.com/tv-and-radio/2022/apr/20/there-was-a-lot-of-torment-the-family-who-endured-two-true-stories
https://www.upi.com/Archives/1981/12/18/The-man-who-kidnapped-young-Steven-Stayner-alternated-sexual/8624377499600/
https://time.com/archive/6883464/nation-escaping-dad/
Wiki