from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
PROMISES, evidence. When a defendant has been arrested, he is frequently
induced to make confessions in consequence of promises made to him, that if
he will tell the truth, he will be either discharged or favored: in such a
case evidence of the confession cannot be received, because being obtained
by the flattery of hope, it comes in so questionable a shape, when it is to
be considered evidence of guilt, that no credit ought to be given to it. 1
Leach, 263. This is the principle, but what amounts to a promise is not so
easily defined. Vide Confession.