Khandro, the great thing about a speech in mitigation is that you can say anything like that without evidence being called to contradict it. You just wait for the judge to say that he attaches no weight to it in sentencing. A regular complaint was that counsel could make any number of suggestions about the character of the victim without any evidence. That's one reason why the victim, or family of a deceased victim, now makes an 'impact statement', to give their side of the story.
Lizzie Borden was not only acquitted of killing her parents with an axe, but her family got every copy of a book consisting of the local press report of the trial destroyed, buying up all they could find ; only about 6 escaped their attentions and have been found since . The report was perfectly fair, but they feared that people reading the case would think her guilty.