Never mind
Destruction of property or terrorism
Arson
Mass Murder (probably)
Terrorism
Property Damage
Specifically a hospital
Destruction of property. It's not a terrorism, because Joker's crime reasons isn't a political or ideological.
Murder of many víctims
Being a evil pice of trash, JK mass murder, arson and destruction of public property
It is called property destruction and mass murder (if people were in the hospital.)
What do you think?