The Bulgarian Umbrella

This deadly umbrella has a hidden pneumatic device that is able to inject a small poisonous dart containing ricin into its targets. On September 7, 1978, a Bulgarian journalist named Georgy Markov was stabbed in the leg with the tip of such an umbrella. He died four days later in a hospital bed. An investigation was launched more than 35 years ago, which is the maximum period. No arrests, accusations, or detentions were ever made.