Ironically, by trying to suppress descriptions of the "victims", the prosecution could easily inadvertently open up the door to the defense being allowed to include character evidence of these "victims". If the prosecution fucks up and describes the purported character of these supposed "victims", such as calling them "good people", or "peaceful protesters", that would open the door for the defense to bring in character evidence against them to show to the jury that the portrayal of the "victims" by the prosecution was.... inaccurate. This could result in things like the "victims" extensive criminal histories becoming part of the evidence. Presently, it is excluded since Kyle had no knowledge of these people or their criminal histories, it was irrelevant to the events of the night. However, if the prosecution tries to portray them as whiter than the driven snow, that will open the door.