Execution
Firing Squad:  Several people shoot and kill a person.  Armies around the world have long used this method, since guns and bullets are readily available.  Firing squad was the lawful means of execution in Finland until 1944, when death penalty was abolished (stopped by the law).  It was also used in the state of Utah in the 20th century.  In most cases, not all the shooters have real bullets.  After the execution, it is not possible to determine which of the people firing killed the person just executed.