It's rarely mentioned because it's irrelevant. He wasn't shot because of the insider trading, and the insider trading doesn't morally justify the shooting.
RE :....Was not shot because of insider trading ...." This could have certainly COULD been a motivation - as some claim to have lost many millions $$$. However , now the accused guy caught - and his motivation claimed to be discerned by his notebook ... Insider trading and fraud accusations if proven in court , show he was dodgy and other in company also dodgy as others suffered BIG losses , claimed in media articles.
Which is weird, because whenever there's a high-profile police shooting the media goes out of their way to dig up dirt on the victim to morally justify the shooting.