He has a doctorate in electrical engineering from the University of Canterbury, and later joined the Government Communications Security Bureau (GCSB), New Zealand's primary signals intelligence agency. He became head of communications security in 1982, and in 1983, he was appointed Director of Policy and Plans. From 1984 to 1989, he was the GCSB's liaison officer to the NSA in Washington. On his return, he became Director of Operations (effectively deputy director of the GCSB), and in 1996, he became the Intelligence Co-ordinator in the office of the Prime Minister. He became the third director of the GCSB in 1999, replacing Ray Parker. In 2006, it was announced that he would succeed Richard Woods as director of another New Zealand intelligence agency, the Security Intelligence Service, on 1 November.
On 1 November 2010, Tucker was reappointed for a further two-year term as Director. He retired in May 2014 with Rebecca Kitteridge taking over his role. In the 2014 Queen's Birthday Honours, Tucker was appointed a Companion of the New Zealand Order of Merit for services to the State.
- Nelson College Old Boys' Register, 1856–2006, 6th edition (CD-ROM).
- Invaluable Service: The secret history of New Zealand’s signals intelligence during two world wars by Desmond Ball, Cliff Lord & Meredith Thatcher p xiii (2011, Resource Books, Waimauku) ISBN 9781877431-23-4
- "GCSB Director to become head of SIS". New Zealand Government. 12 June 2006. Retrieved 11 August 2011.
- "PM announces reappointment of NZSIS director". New Zealand Government. 4 March 2010. Retrieved 11 August 2011..
- "Queen's Birthday honours list 2014". Department of the Prime Minister and Cabinet. 2 June 2014. Retrieved 14 December 2014.
- SIS actions incompetent and unwise