Question: When did the suspected serial killer to which John B. Harman was notable as a medical expert witness for his defence died? 

Context paragraphs:
James E. Aiken: James E. Aiken (born 1941) is the president of James E. Aiken & Associates, Inc.  He serves as a consultant to attorneys and as an expert witness in civil and death penalty cases.  He has served as an expert witness on prison conditions and future inmate dangerousness at U.S. Federal Courts in multiple jurisdictions.  During the trial of 9/11 co-conspirator Zacarias Moussaoui he testified in an expert capacity about what Moussaoui could expect in Federal supermax prison.  From 2004-2009 Aiken served as a commissioner on the National Prison Rape Elimination Commission.

Ambush defence: An ambush defence is one in which defence evidence - notably from expert witnesses - has not been adduced in advance to the prosecuting authorities, leading to their inability to rebut it.  The term is used in United Kingdom jurisprudence.  Since 1987, the possibility of the ambush defence has been much reduced by The Crown Court (Advance Notice of Expert Evidence) Rules 1987, made under section 81 of the Police and Criminal Evidence Act 1984, which in essence require the defence to provide the prosecution with copies of expert witness reports in sufficient time for the prosecution to consider the nature of and if necessary prepare rebuttal evidence opposing the report.

Michael Ashby: Michael George Corbett Ashby, M.R.C.P., F.R.C.P.  (1 November 1914 – 10 December 2004) was a consultant neurologist at the Whittington Hospital, London and an expert witness for the prosecution in the failed trial of suspected serial killer John Bodkin Adams.

Arthur Henry Douthwaite: Arthur Henry Douthwaite (13 February 1896 – 24 September 1974) was a British doctor, Vice President of the Royal College of Physicians and a prolific medical textbook writer.  He was the foremost expert on heroin in Britain in the 1950s, leading to him being called as an expert witness in the trial of suspected serial killer Dr John Bodkin Adams.

John Bodkin Adams: John Bodkin Adams (21 January 1899 – 4 July 1983) was a British general practitioner, convicted fraudster and suspected serial killer.  Between 1946 and 1956, more than 160 of his patients died in suspicious circumstances.  Of these, 132 left him money or items in their wills.  He was tried and acquitted for the murder of one patient in 1957.  Another count of murder was withdrawn by the prosecution in what was later described as "an abuse of process" by the presiding judge Patrick Devlin, causing questions to be asked in Parliament about the prosecution's handling of events.  The trial was featured in headlines around the world and was described at the time as "one of the greatest murder trials of all time" and "murder trial of the century".  It was also described at the time as "unique" because, in the words of the judge, "the act of murder" had "to be proved by expert evidence."

Forensic psychology: Forensic psychology is the intersection between psychology and the justice system.  It involves understanding fundamental legal principles, particularly with regard to expert witness testimony and the specific content area of concern (e.g., competence to stand trial, child custody and visitation, or workplace discrimination), as well as relevant jurisdictional considerations (e.g., in the United States, the definition of insanity in criminal trials differs from state to state) in order to be able to interact appropriately with judges, attorneys, and other legal professionals.  An important aspect of forensic psychology is the ability to testify in court as an expert witness, reformulating psychological findings into the legal language of the courtroom, providing information to legal personnel in a way that can be understood.  Further, in order to be a credible witness, the forensic psychologist must understand the philosophy, rules, and standards of the judicial system.  Primarily, they must understand the adversarial system.  There are also rules about hearsay evidence and most importantly, the exclusionary rule.  Lack of a firm grasp of these procedures will result in the forensic psychologist losing credibility in the courtroom.

John B. Harman: John Bishop Harman, FRCS, FRCP (10 August 1907 – 13 November 1994) was a British physician, president of the Medical Defence Union and chairman of the British National Formulary.  He was also notable as a medical expert witness for the defence in the trial of suspected serial killer John Bodkin Adams.  His daughter, Harriet Harman, is a senior Labour Party politician.

Long Island serial killer: Long Island serial killer (also referred to by media sources as the Gilgo Beach Killer or the Craigslist Ripper) is an unidentified suspected serial killer who is believed to have murdered 10 to 16 people associated with prostitution, over a period of nearly 20 years, and dumped their bodies along the Ocean Parkway, near the remote Long Island, New York beach towns of Gilgo Beach and Oak Beach in Suffolk County, and the area of Jones Beach State Park in Nassau County.

Carole Lieberman: Carole Lieberman M.D., M.P.H. of Beverly Hills, California is a medical doctor, psychiatrist, author, Forensic Expert Witness, and legal analyst providing expert witness testimony for high-profile cases that have included The Jenny Jones Murder Trial, the Jean-Claude Van Damme divorce, the Floyd Mayweather domestic violence case.

Francis Camps: Francis Edward Camps, FRCP, FRCPath (28 June 1905 – 8 July 1972) was a famous English pathologist notable for his work on the cases of serial killer John Christie and suspected serial killer John Bodkin Adams.

Supporting paragraphs: John B. Harman John Bodkin Adams
Answer: 4 July 1983