Poison pen is an improvised weapon which was used in North Korea in a failed attempt to assassinate Park Sang-hak. Poison pen was a set of three pens, disguised as Parker Pens, one of them was fitted with a poison needle and the other two was consisted of a poison-filled bullet and up to three bullets-filled flashlight. The pens became well known for being deadly, although they looked innocuous.
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Poison pen (weapon) Wikipedia(Text) CC BY-SA