Civil rights advocates angry over the death of a student hit by a pepper-spray pellet are circulating petitions seeking a temporary ban on the Boston Police Department's use of so-called "less-lethal" weapons for crowd control purposes. Police Commissioner Kathleen O'Toole last week appointed an independent commission to investigate the Oct. 21 death of Victoria Snelgrove and review weapons like the one believed to have caused the 21-year-old's death during a celebration of a Red Sox victory. But critics of such weapons who held a news conference Thursday said Boston police use of pepper-ball pellets, bean bag projectiles and rubber bullets...