Complex sentence: Calcraft employed the short-drop method of execution, in which the drop through the trapdoor might be around or so, insufficient to break his victim's neck, so death was not instant, and typically occured slowly by strangulation.
Split into simpler sentences: Calcraft employed the short-drop method of execution, in which the drop through the trapdoor might be around or so. This was insufficient to break the miscreant's neck, so death was not instant, and typically occured slowly by strangulation.