I thought the same but then realized that she's speaking in strictly legal methods as if he was on trial. The way people are legally executed are by gas, needle, electrocution, hanging, and even firing squad. So this was official government stuff and likely public to some extent. And when Jason survived all those methods, certain people felt they'd probably rather not risk actually killing him by something like decapitation, because they realize he's immortal, basically, with regenerative capabilities, and want to study him, as we see depicted in the opening of the film.