corpses were available for everyone to dissect. the first recorded body snatching was performed by four medical students who were arrested in 1319 for grave-robbing. in the 1700s most body snatchers were doctors, anatomy professors or their students. by 1828, some anatomists were paying others to perform the exhumation. people in this profession were commonly known in the medical community as "resurrection men". the london borough gang was a group of resurrection men that worked from 1802 to 1825. these men provided a number of schools with cadavers, and members of the schools would use influence to keep these men out of jail. members of rival gangs would often report members of other gangs, or desecrate a graveyard in order to cause a public upset, making it so that rival gangs would not be able to operate. selling murder victims from 1827 to 1828 in scotland, a number of people were murdered, and the bodies were sold to medical schools for research purposes, known as the west port murders. the anatomy act of 1832 was created to ensure that relatives of the deceased submitted to the use of their kin in dissection and other scientific processes. public response to the west port murders was a factor in the passage of this bill, as well as the acts committed by the london burkers. stories appeared of people murdering and selling the cadaver. two of the well-known cases are that of burke and hare, and that of bishop, may, and williams. burke murdering margery campbell burke and hare – burke and hare ran a boarding house. when one of their tenants died, they brought him to robert knox's anatomy classroom in edinburgh, where they were paid seven pounds for the body. realizing the possible profit, they murdered 16 people by asphyxiation over the next year and sold their bodies to knox. they were eventually caught when a tenant returned to her bed only to encounter a corpse. hare testified against burke in exchange for amnesty and burke was found guilty, hanged, and publicly dissected. london burkers, bishop, may and williams – these body snatchers killed three boys, ages 10, 11 and 14 years old. the anatomist that they sold the cadavers to was suspicious. to delay their departure, the anatomist stated that he needed to break a 50-pound note and sent for the police who then arrested the men. in his confession bishop claimed to have body-snatched 500 to 1000 bodies in his career. making cars safer prior to the development of crash test dummies, cadavers were used to make motor vehicles safer. cadavers have helped set guidelines on the safety features of vehicles ranging from laminated windshields to seat belt airbags. the first recorded use of cadaver crash test dummies was performed by lawrence patrick, in the 1930s, after using his own body, and of his students, to test the limits of the human body. his first use of cadaver use was when he tossed a cadaver down an elevator shaft. he learned that the human skull can withstand up to one and a half tons for one second before experiencing any type of damage. in a 1995 study, it was approximated that improvements made to cars since cadaver testing have prevented 143,000 injuries and 4250 deaths. miniature accelerometers are placed on the bone of the tested area of the cadaver. damage is then inflicted on the cadaver with different tools including; linear impactors, pendulums, or falling weights. the cadaver may also be placed on an impact sled, simulating a crash. after these tests are completed, the cadaver is examined with an x-ray, looking for any damage, and returned to the anatomy department. cadaver use contributed to ford's inflatable rear seat belts introduced in the 2011 explorer. public view of cadaver crash test dummies after a new york times article published in 1993, the public became aware of the use of cadavers in crash testing. the article focused on a heidelberg university's use of approximately 200 adult and children cadavers. after public outcry, the university was ordered to prove that the families of the cadavers approved their use in testing.