Because if he testifies he opens himself up to cross examination. He stands a better chance by not doing that - his chance is that at least one juror votes not guilty regardless of the actual case/facts/etc.
And your attorney if any good in a case like this would not let you because while it may say a lot to not say anything, it says even more if cross-examination brings out/emphasizes contradictions and makes it harder for anyone on the jury to justify "not guilty."
Because if he testifies he opens himself up to cross examination. He stands a better chance by not doing that - his chance is that at least one juror votes not guilty regardless of the actual case/facts/etc.
And your attorney if any good in a case like this would not let you because while it may say a lot to not say anything, it says even more if cross-examination brings out/emphasizes contradictions and makes it harder for anyone on the jury to justify "not guilty."