At our school, my friend got loads of those fake blood capsules and burst them on the ground outside a building, we went upstairs and opened the window really wide, and then he lay on the ground where all the blood capsules were burst and had some blood capsules in his mouth, so blood was flowing out. We got a girl to scream, to get people's attention.
We had like hordes of people crowding around, and then this teacher came, got through the crowd,
and saw the guy on the ground with blood all around him, and we said he jumped, and the teacher turned around, stumbled to his car and leaned against it with a shocked face. A few other teachers were scared to death too, but before anyone called 911 (it's surprising how long it actually takes people to dial 911) he got up and walked away.