Accurate information is important, there's no use trying to shame people out of being interested in the facts.
It's important to know the sex of the offender at the time of the event if the gunman is still on the loose - if people are told it's a woman, that's what they look out for, not a man in a dress. That could cost lives. You surely don't think that's of less importance than affirming a murderer's ideas about himself?
It's also important after the event, so that accurate statistics can be compiled, trends identified, and measures taken to mitigate other incidents in the future. It is the case that there have been several mass shootings by trans identified individuals. What exactly do you think will be the use in putting our fingers in our ears and going 'la la la, don't want to hear it, don't want to know' about that?
You purport to care about the victims here, so presumably you care that any future victims are avoided, as far as possible? In which case, preventative measures should be taken and that would be impossible to do effectively without a very clear idea of who carries out these attacks and why.
Facts, truth, reality and evidence matter.