From Law wiki, the wiki for law research

Jargon term for a statement made by the defendant in a criminal trial, other than during his testimony, which contains a mixture of Exculpatory and Inculpatory elements. An inculpatory statement -- a Confession, in other words -- is prima facie admissible against the defendant, even though it amounts to Hearsay. A purely exculpatory statement is, in general, not admissible, because it adds nothing to the probative value of the defendant's evidence. However, if a statement contains both inculpatory and exculpatory elements, it is likely to be admissible in its entirety (R v storey (1968)), because it would be unfair to the defendant to edit out the inculpatory parts before putting the statement before the jury. Nonetheless, the judge is entitled to warn the jury that the inculpatory parts have more weight (R v duncan (1981)).