Phillip Garrido 'Thanked for Cooperation' July 9, 2011 - They are words of courtesy and encouragement that have come back to haunt Mark Messner: "I hope that you will continue to do well. If there is anything we can help you with in the future, do not hesitate to contact our office. Messner, a senior U.S. probation officer who works for the California's northern district probation office, included those sentences in a May 17, 1999 letter to Phillip Garrido, the man later convicted of kidnapping, raping and holding Jaycee Dugard captive for 18 years. Garrido had kidnapped Dugard in 1991, when she was 11 years old, and went on to father two children with her. At the time of the kidnapping, Garrido had already had a violent sexual history. In 1977, he kidnapped and raped a woman named Katie Callaway Hall in Nevada. For that crime, Garrido received a 50-year federal sentence. But he would see only 11 years of jail time before the federal government paroled Garrido and then released him to authorities in Nevada, where he briefly served a state prison sentence for his rape of Hall. After serving that sentence, he moved to California and served the remainder of his federal parole term. Messner was one of the federal probation officers assigned to supervise Garrido's parole between January 1988 and March 1999, when the U.S. probation service decided to terminate Garrido's federal parole, leaving his supervision up to state authorities. In his 1999 letter, Messner confirmed Garrido's "early termination" from federal parole and thanked him for his "cooperation." Authorities in Nevada briefly took over supervision of his parole in 1999 before the responsibility was transferred to the California Department of Corrections and Rehabilitation under the terms of an interstate parole compact. Like officers with the U.S. Parole Commission, California Department of Corrections and Rehabilitation parole officers also went years without discovering Garrido's latest crimes. ABC News called Messner and asked him to talk to us about the Garrido case. We wanted him to talk to us about why the federal parole service failed to detect Jaycee Dugard and her children living at Garido's house. Both Messner and his supervisor said the U.S. Parole Commission had prohibited them from discussing the case. "20/20" anchor Chris Cuomo caught up with Messner as he was returning to his home in Novato, Calif. Cuomo tried to ask him about the Garrido case, but Messner refused to get out of his car and drove off. Johanna Markind, of the U.S. Parole Commission's Office of the General Counsel, told ABC News that the commission declined to comment on the case because the commission's own evaluation of the Garrido case is still ongoing. Watch the full story, including Jaycee Dugard's first television interview, on ABC, Sunday at 9 p.m. ABC News' Cleopatra Andreadis contributed to this report.