There is no solution to this problem.
Some people will always choose to go out in a percieved blaze of glory by taking others with them.
This guy was a coward. Afraid to take his own life without first taking others with him... He is no different than Jim Jones exept that he couldn't lead a cult following (he was a complete zero whereas Jones was a less-than-zero)...
Here's to hoping he and Jim Jones suffer an eternity in hell while their victims find peace and happiness that those basterds tried to steal away from them.
