Maiming strike
rogue attack 19
Requirement: wielding a crossbow, a light blade, or a sling.
Target: one creature
Attack: Dexterity vs. AC
Hit: "4[W] + Dexterity modifier damage."
Effect: you knock the target prone. The target is slowed, cannot shift, and cannot charge (save ends all).[MP2:68]
Maiming strike is a daily power available to rogues at 19th level.