Which is really ironic, as my late father is the formal registered inventor of the Folding Crossbow.
https://patents.google.com/patent/US4926834A/en
No, this one isn't a folding crossbow, but it does seem powerful enough to potentially be deadly. It's raining today so I'll have to wait for a good weather day and find an old used slab of wood for target practice.
I used to have one exactly like that, years ago. Came with about 2 dozen bolts, blue, yellow, orange, and red. It shot ok, about a dinner plate sized pattern at 10 yards. If you shoot a dense foam archery target you'll want a pliers to pull the bolts out, because only an inch or two will be sticking out of the target. Shooting hard wood will break the bolts, if it's half rotten it will be fine.