( CNN ) -- In his time as a New York City police officer , Stephen Spiro says that it only happened to him once . Typically , the people he arrested wanted nothing to do with him . But then , few things about the case of Mark David Chapman were typical . Chapman , the man convicted of killing former Beatle John Lennon , wrote Spiro , his arresting officer , four letters . In the letters , Chapman repeatedly tells Spiro to read `` The Catcher in the Rye , '' saying the book would explain much of what happened the night of the murder , December 8 , 1980 . He expresses an ease with the officer , saying he hoped they could be friends , that he thought Spiro was a great policeman , and that he had felt close to him ever since his arrest . Chillingly , Chapman also wrote that others `` could -- and would -- have served the same purpose '' as Lennon . The four letters are expected to go on sale Monday on the Moments in Time website , which sells rare autographs and historical documents . Spiro says they represent the only time someone he arrested wrote him letters . `` They 've been in my possession for 30 years , and I 'm 66 years old , and I 'm saying , you know , what am I going to do with these things ? So I figured I 'd sell them , '' he told CNN . The letters run from January to May 1983 . Each one is typed and includes Chapman 's signature . Spiro says he wrote a few letters in return , but Chapman `` cut it off after a while . '' The two men spent several hours together immediately after Chapman 's arrest . He trusted Spiro . Chapman , who was denied parole for the seventh time in August , is serving a sentence of 20 years to life . The letters will be on sale for $ 75,000 , said Gary Zimet , who runs the Moments in Time site . The site is also selling a `` Double Fantasy '' record album , which Lennon signed for Chapman before his murder , for $ 650,000 . Spiro said that he plans to donate some of the money he makes to a local shelter for battered women . Here are excerpts from Chapman 's letters : . January 15 , 1983. `` ... I am glad that we can keep in touch . I 'll not forget the first time we met ... `` Besides wanting to be your friend , there are two reasons for this first letter . First , is there any way that you can help me locate my copy of The Catcher in the Rye that was taken from me on the night of my arrest ? Second , in the patrol car on the way to the stationhouse , I remember you telling your partner -- very excitedly -- that you KNEW something big was going to happen to you on that evening . Do you remember this ? I would like you to tell me more of this if possible . `` Steven , have you read The Catcher in the Rye yet ? I would like you to read it and tell me what you think of it . As you remember , in the copy that was taken from me I had written 'This is my statement ' . I am wondering if you now understand this . `` Write soon . Let me know how you 're doing . As I 've said before , you 're probably still the 'best damn cop in New York City'. `` January 28 , 1983 . `` ... The reason I wanted to write was from the time of my arrest I have felt close to you ... `` To answer your question of what was meant by 'This is my statement ' , the only way I can explain is this way : do you remember the young woman in Saigon during the Vietnam war that immolated herself ? ... She believed so strongly in her purpose that she chose to end her life rather than to continue living in this phony world ... `` The Cather in the Rye is my statement . The book in incredible ... `` We were all part of something big , Steve . Something phenomenal . It is all going to come out . '' March 10 , 1983 . `` ... You mentioned your family . Tell me about your children . How about a photo , too ? `` Have you read The Catcher in the Rye yet ? I know this will help you to further understand ... `` I will let you decide whether Mr. Lennon was a phony or not . His words shoot his life-purpose full of holes . If you dig deep -- and not idolize -- it is all there . Yes , Lennon was a phony of highest degree but there were others who could -- and would -- have served the same purpose . I believe the DA has these names . '' May 31 , 1983 . `` Read The Catcher in the Rye . `` Sincerely , Mark David Chapman . '' CNN 's Adam Reiss reported from New York and CNN 's Dana Ford from Atlanta . CNN 's Ross Levitt also contributed to this report .
John Lennon wrote letters to the New York City police officer who arrested him . He repeatedly tells the officer to read the book , `` The Catcher in the Rye says others `` could -- and would -- have served the same purpose '' as Mark David Chapman . He killed Lennon in 20 years and is serving a sentence of 1980 to life in prison .