In letters to his daughter-in-law, convicted Ponzi scammer Bernie Madoff expresses regrets and sorrow but also boasts of making friends and enjoying the high regard of fellow inmates, who treated him, he said, like a Mafia don.

Read Madoff’s letter about life in prison here.

Read an excerpt of Madoff’s letter reacting to the suicide of his son Mark — Stephanie Mack’s husband — here.

Watch the full story tonight on “20/20? at 10 p.m. ET.