How on earth can anyone do this without a guillotine-like device?
All it takes is a rope.
Happened before.
The same way certain Clinton associates shot themselves in the back of the head with a shotgun.
Chain saw?
Yep, eight shots to the head … worse case of suicide ever seen by local police.
Give me a break, self-decapitation … no way.
Long wire tied around the neck, other end run out the window and tied to some stationary object such as a concrete pillar. Or loop the middle of the wire around neck & tie both ends to the pillar. Stomp on the gas... A bit like a wire cheese slicer only more horsepower. Could be other ways I guess.
He must have used a Toledo Salamanca.
An earlier story said he had tied a rope around a streetlight pole, and the other end of the rope to his throat, and gunned the car forward, tearing his head off.
Very easily. It isn't so much a matter of neatly slicing the head off, as it is forcefully tearing the head from the body.
In the American West, when they hanged criminals, executioners had to be very careful to use the right rope. If the drop was too high or the rope was too thin or too rigid, the head could tear clean from the body.
There were tables that showed the drop height taking the condemned criminal's weight into account to prevent it from happening.
Still it did happen from time to time. In 1901, Tom "Black Jack" Ketchum was a train robber and outlaw. He was caught and was sentenced to hang.
Ketchum gained weight in jail while waiting for his sentence to be carried out, and the executioners were inexperienced, so when he was hanged, his head came clean off. Only the hood, which had been pinned to his shirt, kept his head from rolling away.
There was a photographer on the scene and there are photos of him immediately before and after his hanging. Here is a short story with both photographs (^). The link is to page 1, the hanging photos are on page 2. Needless to say, they are graphic.