Snipers are dangerous enemies that can kill you with one shot. However, if you avoid their laser sights, they will not see you. Unlike other enemies, snipers do not patrol, but instead focus their full attention on a small but deadly arc in front of them, though this makes them easier to sneak up on. They can be distracted in order to temporarily get them to move their sights elsewhere.
There's a possible bug where kicking a sniper can fail a "no damage taken" seal type.