Poindexter was born in Odon, Indiana, the son of Ellen (Sommers) and Marlan G. Poindexter. He received his undergraduate degree from the United States Naval Academy in 1958, where he graduated first in a class of 899. His fellow graduates included astronaut Bruce McCandless II (who graduated second) and Senator John McCain; fellow National Security Advisor Robert McFarlane graduated the following year.
Poindexter received an M.S. (1961) and Ph.D. (1964) in nuclear physics from the California Institute of Technology. For his dissertation, he conducted laboratory research to further develop a model for understanding the Mössbauer effect with Nobel Laureate Rudolf Mössbauer.
Senior naval career
While commander of a destroyer squadron, he was surface warfare and anti-submarine warfare commander of battle groups in the Western Pacific Ocean and Indian Ocean, and he developed new tactics and battle management procedures under the Composite Warfare Commander concept. As the commanding officer of USS England, he pioneered the shipboard use of computers to manage the ship's force portion of yard overhauls.
He was also an executive officer and a chief engineer of destroyers.
As Deputy Commander of the Naval Education and Training Command, his duties included commanding the United States Navy's extensive education and training programs, for which he initiated a project to develop a distributed data management system for more efficient management of training pipelines.
His significant staff assignments included: Executive Assistant to the Chief of Naval Operations, Administrative Assistant to the Secretary of the Navy and Special Assistant for Systems Analysis to the Secretary of Defense. He reached the temporary rank of Vice Admiral but was allowed to retire in 1987 at the lower rank of Rear Admiral as a result of his role in the Iran–Contra affair.
Poindexter went on to serve in the Reagan administration as Military Assistant to the National Security Advisor (1981-1983) and Deputy National Security Advisor (1983-1985) prior to his appointment as National Security Advisor (1985-1986). From 1983 to 1985, Poindexter was responsible for leading and managing the National Security Council staff as chairman of the Crisis Pre-planning Group. As National Security Advisor, Vice Admiral Poindexter was responsible for providing recommendations to the President on national security, foreign policy and defense policy.
Major events in which he played a significant role for the executive branch included the Strategic Defense Initiative, Operation Urgent Fury, the Achille Lauro incident, Operation El Dorado Canyon (in response to Libyan terrorist attacks), and the Reykjavík Summit with the Soviets.
The Iran-Contra affair resulted from the discovery of the United States' involvement in sending money and weapons to Iran for the release of American hostages from Lebanon, and sending aid to the Contras. This involvement was in violation of the Boland Amendment which prevented the United States from directly or indirectly being involved with the Contras. Evidence revealed that Poindexter was a leader in the organization of the transfer of the weapons to Iran and oversaw other people involved in the affair, such as Oliver North.
Poindexter and North communicated through a channel known as the "Private Blank Check" which Poindexter set up on a National Security Council (NSC) computer. Through this system, Poindexter and North were able to send messages back and forth without being intercepted by other NSC staff members. This system was not successful. Even though both Poindexter and North attempted to delete the messages, the White House Communications Agency was able to recover some of them, later used in trying Poindexter and North. On November 25, 1986, after the public disclosure of the Iran-Contra affair, Poindexter was forced to resign from his position as National Security Advisor.
Poindexter was convicted on April 7, 1990, of five counts of lying to Congress and obstructing the Congressional committees investigating the Iran-Contra Affair, which were investigating the Reagan Administration's covert arms sales to Iran and the diversion of proceeds to insurgents fighting to overthrow the Sandinista government in Nicaragua. The convictions were reversed in 1991 on appeal on the grounds that several witnesses against him had been influenced by his testimony before Congress, even though Congress had given him immunity for that testimony.
From 1988 to 1989, Poindexter was senior scientist at Presearch, Inc., which had primarily been involved with defense studies and analysis. Faced with anticipated defense budget reductions, Poindexter joined the firm to develop new commercial enterprises. He designed and developed hardware and software for the prototype of a digital real-time imaging system to be used for physical security of high value facilities. It was used to obtain a contract for a nuclear power plant security system.
From 1990 to 1996, Poindexter served as co-founder of TP Systems, Inc., a software development firm specializing in commercial software for the IBM PCs and compatibles; Poindexter was the chief designer and programmer. Development included a symbolic debugger for multi-tasking environments, a BBS communications program, and numerous utility programs.
From 1993 to 1996, Poindexter served as a consultant to Elkins Group. Elkins was a business alliance with Electronic Data Systems (EDS), which has developed the Elkins Interactive Training Network (EITN), a satellite-based training delivery system. Poindexter was the chairman of the Maritime Advisory Committee and a member of Elkins' board of directors. He also provided advice on strategic planning.
From 1996 to 2002, Poindexter served as senior vice president for SYNTEK Technologies. SYNTEK is a small high technology firm with contracts in domestic and international defense and commercial business. Poindexter was responsible for high-level advice on management and direction of information systems projects (for example Defense Advanced Research Project Agency's Project Genoa).
Currently, he serves on the board of Saffron Technology which he joined in 2000 and Bright Planet Corporation which he joined in 2007. With Saffron, Poindexter played a role in Iraq, building a tool to run entity analysis on insurgent networks in the struggle against IEDs.
After 2007, Poindexter branched out from National Security and worked to promote Associative Memory Base technology to civilian government agencies such as the IRS for fraud detection.
Late in 2001, upon the recommendation of Science Applications International Corporation executive Brian Hicks, then Vice President Dick Cheney recommended Admiral Poindexter to head a separate anti-terrorist office and serve under US Secretary of Defense Donald Rumsfeld.
From January 2002 to August 2003, Poindexter served as the Director of the DARPA Information Awareness Office (IAO). The mission of the IAO was to imagine, develop, apply, integrate, demonstrate and transition information technologies, components, and prototype closed-loop information systems. This aimed to counter asymmetric threats (most notably, terrorist threats) by achieving total information awareness and thus aiding preemption; national security warning; and, national security decision making.
Poindexter faced criticism from the media and some politicians about the Policy Analysis Market project, a theoretical prediction market that would have rewarded participants for accurately predicting geopolitical trends in the Middle East and elsewhere. This was portrayed in the media as allowing participants to profit from the assassination of heads of state and acts of terrorism due to such events being mentioned on illustrative sample screens showing the interface. The controversy over the proposed futures market led to a Congressional audit of the IAO in general. Funding for the IAO was subsequently cut and Poindexter retired from DARPA on August 12, 2003.
His wife, Linda Poindexter, was an Episcopal priest for 13 years, but retired from the clergy when she converted to Catholicism. They have five children, including the late Alan G. Poindexter, a NASA astronaut, Space Shuttle pilot on the STS-122 mission to the International Space Station, and the commander of STS-131.