This is from the TDCAA Case Summaries, relating to Walters v. State from the CCA, 12/5/07:

quote:

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A defendant is typically not permitted to introduce his self-statements into evidence. But, if the State has introduced some of his statements into evidence (such as through the telephone call in this case), all of those statements must be admitted into evidence if they deal with the same subject, even if the statements are otherwise inadmissible.

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I don't think Walters takes it that far. Simply because you introduce part of a statement doesn't make it all admissible unless you leave a false impression. In Walters, the complaint was that the fact that Walters talked to the 911 operator was admitted, but the fact that he told the 911 operator he had shot in self defense was kept out. The Court found that this left a false impression that the defendant had remained silent when asked about what happened, when in fact he had given a statement consistent with his trial testimony.

If you offer part of a defendant's statement, you can still object to the rest unless the part you've offered leaves a mistaken impression that the remainder of the statement will counteract.