Perhaps allowing an 8-year-old to fire an Uzi is to the Second Amendment what allowing one to read Hustler would be to the First Amendment

Perhaps not. Setting all subjective moral beliefs aside, however, in the United States of America it is actually legal to allow a young child to fire an Uzi while allowing one to read Hustler would most certainly provide legal grounds for an inquiry from Child Protective Services likely to result in diminished parental rights and/or jail time. The adults who allowed this horrific shooting death to occur are as likely to face jail time as Hustler is to go out of business.