According to Official Guinness Records,
Psychiatrists have been acting as expert witnesses since at least the mid-1840s, but the first referenced use of a psychologist called upon to testify in a court of law was Dr Albert Von Schrenk-Notzing (Germany, 1862-1929) who, in 1896, drew upon his studies of suggestibility and memory recall to testify in a murder trial. His testimony related to the difficulties in accepting witness statements after the trial's intense pre-publicity – an issue that continues to affect trials today.Dr Schrenk-Notzing drew up his experimental studies at the institute run by W. Wundt (Germany). He argued in court that certain witnesses could not distinguish between what they had actually seen and what they had already read in the press.
For a complete list of 1896 records, please visit 1896 Guinness Records in Germany.