He was abducted in 1960 by Mossad, Israels foreign intelligence agency, put on trial in Israel and executed in 1962.
The documents show that the CIA was in possession of Eichmanns pseudonym two years before the Mossad raid. The CIA received this information in 1958 from the West German government, which learned of Eichmanns alias in 1952.
Both the CIA and the Bonn government chose not to disclose this information to Israel because they were concerned that Eichmann might reveal the identities of Nazi war criminals holding high office in the West German government, particularly Adenauers national security adviser Hans Globke.
When Eichmann was finally brought to trial, the US government used all available means to protect its West German allies from what he might reveal. According to the declassified documents, the CIA pressured Life magazine into deleting references to Globke in portions of Eichmanns memoirs that it chose to publish.
In addition to the revelations regarding Eichmann, the documents chronicle the CIAs creation of stay-behind intelligence networks in southwestern Germany and Berlin, labeled Kibitz and Pastime, respectively.
The Kibitz ring involved several former SS members. In the early 1950s, the CIA provided these groups with money, communications equipment and ammunition so that they could serve as intelligence assets in the event of a Soviet invasion of West Germany.
The CIA documents were reviewed by Timothy Naftali, a historian with the National Archives Interagency Working Group, the government body that oversaw their declassification and release. According to an article published by Naftali, the stay-behind program was dissolved in the wake of public concerns in West Germany about the resurgence of Neo-Nazi Groups.
Specifically, the Kibitz-15 group, led by an unreconstructed Nazi, became a potential source of public embarrassment for the US, as its members were broadly involved in Neo-Nazi activity. 
The CIA terminated the program by 1955 and arranged for many of its contacts to be resettled in Canada and Australia. According to the documents, Australia provided funds for relocation while the CIA provided its ex-assets with a resettlement bonus.
The CIA employed Gustav Hilger, a former adviser to Nazi Foreign Minister Joachim von Ribbentrop. As an employee of the German foreign office, Hilger was present at the negotiation of the Stalin-Hitler pact in 1939. The CIA deemed his experience with the USSR sufficiently valuable to free him from incarceration at Fort Meade in Maryland and employ him as an intelligence evaluator in West Germany.
In 1948, Hilger moved to the United States and obtained a position at the CIAs K Street building in Washington as a researcher and expert on the USSR. Hilger eventually left the CIA to work for the West German foreign office.
According to a paper analyzing the CIA documents published by Robert Wolfe, a former senior archivist at the US National Archives, it is beyond dispute that Hilger criminally assisted in the genocide of Italys Jews.... During the roundup of Italian Jews in late 1943, a note signed Hilger recorded Ribbentrops concurrence that the Italians be asked to intern the Jews in concentration camps in Northern Italy, in lieu of immediate deportation. The SS intended thereby that the Italian Jews and their potential Italian protectors should believe that internment in Italy was the final destination, rather than eventual deportation to the murder mills in Poland to be immediately murdered or gradually worked to death. The stated purpose of this ruse was to minimize the number of Italian Jews who would go into hiding to avoid deportation to Poland 
In another instance, the CIA employed Tscherim Soobzokov, a former Nazi gendarme and Waffen SS lieutenant, who, according to a paper published by Interagency Working Group Director of Historical Research Richard Breitman, participated in an execution commando [combat group detailed to executing Jews and Communists en masse] and had searched North Caucasian villages for Jews.
Soobzokov was employed by the CIA for seven years. Over this period, he repeatedly used his intelligence contacts to avoid investigation by the FBI and the US Immigration and Naturalization Service (INS) in regard to his complicity in war crimes.
According to Breitmans paper, CIA examiners noted that Soobzokov was an incorrigible fabricator who repeatedly lied about his past in order to conceal his participation in criminal activity. Nevertheless, the CIA shielded him against investigation, at one point sending the INS a document asserting that Soobzokov had never worked for the Nazis. 
Prior to the outbreak of war, a significant section of the American ruling elite had favored cooperation with the Nazis as a European hedge against the spread of Bolshevism. Henry Ford was notorious for his anti-Semitism and his political affinity for German Fascism, and a number of major American companies retained their business ties with the Third Reich. Notably, IBM sold Germany the punch cards that were used to catalog the final solution. (See: How IBM helped the Nazis IBM and the Holocaust)
However, as one European nation after another fell before Hitlers onslaught, the threat of German imperialist dominance in Europe spurred the American ruling class to enter the European theater.
US imperialism mobilized popular support in its war against the Nazi regime by appealing to the democratic and anti-fascist sentiments of the American people. After the defeat of Germany, it organized, together with its World War II alliesBritain, the Soviet Union and Francethe Nuremburg trials to prosecute top Nazi officials for their complicity in war crimes.
However, with the start of the Cold War, the United States reversed its policy of identifying, trying and executing prominent Nazi war criminals. As is starkly demonstrated in the case of Eichmann, the knowledge possessed by many of these individuals made trying them inconvenient.
Regardless of its limited prosecution of upper-echelon Nazis, the United States had no qualms about recruiting Nazi Party members and war criminals into its military research apparatus. Prominent German military developers such as Werner Von Braun and Bernhard Tessmann were assimilated into the US rocketry program, while Kurt Blome, a Nazi scientist who experimented on concentration camp prisoners, was employed by the US to develop chemical weapons.
Likewise, the early stages of the Cold War saw high-level Nazi cadres drafted into the US intelligence machine and deployed in Europe, the Middle East and the Americas. According to the Department of Justice Office of Special Investigations (OSI), the bureau assigned to investigate German war criminals living within the US, at least 10,000 Nazis entered the US between 1948 and 1952. Of the thousands of German Nazis who fledor were broughtto the United States, only some 100 have been prosecuted by the OSI.
1. Timothy Naftali, New Information on Cold War CIA Stay-Behind Operations in Germany and on the Adolf Eichmann Case http://www.fas.org/sgp/eprint/naftali.pdf
2. Robert Wolfe, Gustav Hilger: From Hitlers Foreign Office to CIA Consultant http://www.fas.org/sgp/eprint/wolfe.pdf
3. Richard Breitman, Tscherim Soobzokov http://www.fas.org/sgp/eprint/breitman.pdf