Although this was early days in the history of DNA profiling, it is difficult to credit the police felt obliged to offer Karla any kind of deal in order to secure a conviction; the case against Bernardo was surely compelling enough without her testimony. In the UK, the two would most certainly have been charged together, and if Karla ever saw the light of day again it would have been as an old woman rather than as a relatively young one who some miserable wretch not only impregnated but married and whisked off to an island paradise.
Did Karla rather than Bernardo kill the two girls? Bernardo’s lawyer seems to think so; the man himself said so, and as he has since confessed to numerous other crimes that will ensure he is never released, there is no good reason not to believe him.