Journalist Jack Jones, who authored a book on the killing, gave more than 40 hours worth of taped interviews to the production company for a special scheduled for air on Britain's Channel 4.
Chapman has said he killed Lennon in an attempt to "steal his fame," but a Channel 4 spokeswoman denied claims the program was helping Chapman achieve the goal.
"It's John Lennon's assassination, seen through the eyes of Mark Chapman," she said.
"The program will give viewers an insight into what was going on in his mind and what his motivation was.
"It is a serious documentary. It is not about Chapman as a character but why did he do this and the psychological reasons behind it."
Channel 4 said Chapman, his friends and his family have not been payed for the interviews.