I have devised the perfect crime in which it is impossible to be caught.

I could do a perfect crime If I wanted to. I will defeat every forensic weapon the cops have, I will leave no evidence (besides a trail of bodies) I will kill everyone in my path.

Say, If I was to rob a bank. First, I will need weapons. I can buy illegal guns or weapons that are registered to me. Say I use legal weapons. I use wooden and "fireball" rounds in my rifle and rifled slugs, birdshot, buckshot in my shotgun. I collect every spent case. My ammo will not live my own fingerprints on them.
The wooden bullets do not adapt to the rifling, therefore cannot be forensically traced. shotgun has a smooth bore. No rifling, no way to prove that my gun did the killing.
We all wear hair nets, shower caps to prevent hair from falling at the crime scene.
We all wear burnable gloves so we don't actually touch anything.
My bank is a bank much like the one in "inside Man" movie, similar layout that is hard the get in, but easy to leave. I devise an exit strategy. None of my plans exist on paper or electronically. I do not talk of my crime or mention anything about it.
I make sure I'm a dead accurate shot
All my ammo are bought locally at high-volume stores and with cash only. I use a IR lamp so that while I'm at he counter the camera gets nothing but white light. Humans can't see IR light.
I bring smoke grenades and flash bangs
I use a thermite bomb to destroy all the surveillance equipment in bank.
I use hostages and a flatbed truck. and two other partners.
My plan is simple. go in the rob the place, shoot all the computers, cell phones. using the crowbar I rip the camera out and throw them all into the server/surveillance equipment room. A thermite bomb generates up to 6000 deg F, which will destroy the contents of the room, all data stored.
Then we leave.

Learned from the Hollywood bank robbery, it doesn't always go to plan. a back up strategy is around, where using the rifle and special ammo, we clear a 800 yard area from the bank by shooting everyone in that area. Using a spud gun we set nearby buildings and cars on fire with thick, black smoke. Smoke grenades give us cover as we load hostages into the back of the truck.
In this case, we douse the bank in gas and burn it.
we leave with all hostages and cops in pursuit. according to escape plan (exit strategy) we go to an open, empty road (like the channelized LA river- more movies) and allow cops to catch up. call them and say if they don't stop casing us, we kill all hostages. To show them we mean it, light a hostage on fire and shove the burning hostage from the truck to the cops can run over the flaming body.

they back off, we shoot down the chopper.
someplace far far away we let the hostages go, kill them all, burn the truck and all gloves, etc. change clothes, put guns away, take the money and get into a secondary vehicle nearby. the vehicle is on asphalt so not tire tracks are left behind.

the money is split up and everyone goes their separate ways.

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And that's how you can do a perfect crime. no evidence, no forensics, the cops have dozens of dead bodies, a burned truck and burned down bank. A downed chopper. They have massive destruction and yet no evidence to convict anyone.

to be safe you could always shoot the partners and take all the money yourself. cremate the bodies.

the money is carefully spent, if you go on a spending spree people will know something is up. I get a better job and spend a little more money. I behave as a model citizen. I'm never caught and the crime never solved.
Source(s):
perfect crimes are easy to do. all you need is to be very smart. and very dangerous.