John George Haigh commonly known as the "Acid Bath Murderer" , was an English serial killer

Serial killer

A serial killer, as typically defined, is an individual who has murdered three or more people over a period of more than a month, with down time between the murders, and whose motivation for killing is usually based on psychological gratification...

 during the 1940s. He was convicted of the murders of six people, although he claimed to have killed nine. He did not use acid actually to kill his victims, but rather as (he believed) a foolproof method of body disposal – dissolving their bodies in concentrated sulphuric acid before forging

Forgery

Forgery is the process of making, adapting, or imitating objects, statistics, or documents with the intent to deceive. Copies, studio replicas, and reproductions are not considered forgeries, though they may later become forgeries through knowing and willful misrepresentations. Forging money or...

 papers in order to sell their possessions and collect substantial sums of money.