Like this or different?
Different. Ampoules are used by first snapping of the top, then inserting a needle and withdrawing the medication, then ejecting the air in syringe, then injecting the medication. This process takes a while and is kind of hard to hide.
More likely they would use an epi-pen type injector.
Yes...They are sometimes also called “cassettes” but they are not like what people think of when they of “cassette” it is more a cartridge.