Habemus optimum testem, confitentem reum is a legal maxim in Latin. It means ‘ we have the best witness, a confessing defendant.’
The following is an example of a case law referring to the maxim:
Habemus Optimum Testem, Confitentem Reum (1 Phil. Ev. 397). The matter sub judice illustrates the timelessness of this ancient maxim. Since the days when prosecutors held the title of tribune and tried their cases before the Comitia Centuriata, a confession has often been considered the most valued weapon in a prosecutor's arsenal. Like the legendary sword of Brennus, once it has been thrown onto the scales all but the most obdurate of juries will generally yield. Because in times past, as in the present day, this created an understandable impulse (in [**2] less than scrupulous minds) to obtain a less than genuine admission of guilt, learned authorities of the common law came to question the fairness of its use at trial. In his commentaries on the treason statute of King William III, Sir Michael Foster noted the restrictions on the use of out of court admissions and finally declared that the most favored form of admission was one taken before a magistrate, "…when the Party may be presumed to be properly upon his Guard, and apprized of the Danger he standeth in." (Sir Michael Foster, Discourse on High Treason, Article 3, Section 3, Clauses 1 and 2 ).[PEOPLE v. TATUM, 2001 NY Slip Op 40012U ].