A Doppelarmbrust is a double decker crosswbow. The first bolt you usually fire is filled with Hellebore Extract that acts like a tranqualizer, ment to slow down the attacker. The second bolt is filled his hemlock, just in case the firet bolt doesn't work. This weapon was specifically designed for killing Blutbaden. However, they can also kill other Wesen, as Slivitch tried to kill Nick after he killed his friend by accident, and Nick fired the crossbow into Slivitch's throat. Slivitch was a Hässlich, and a Reaper.