Show was wan caa casts ts are help to cops in shooting cases milwaukee police department bartme part ment nt has adopted a new method in criminal investigation whereby a person who has fired a gun can be do da by chemical analysts analysis of a wax cast of their hands the idea was adopted fol following lowling a visit made to the city by teodoro gonzales assistant director of the bureau of criminal investigation mexico cit city the basis of the test is that the discharge of a shell leaves microscopic particles particle s of powder on the skin of the hands melted paraffin to la poured over the hand of the suspected acted person r removed 0 when hard and subjected to chemical analysts analysis if the hand on which the the mold ts is taken has hag fired a gun traces of the nitrate base of powder will show up in the analysis police chief jacob 0 Lauben helmer became interested and conducted a number of tests four officers a were sent to the police target practice room with instructions that one of them was to fire his gun in each case the identity of the officer that fired alred the gun was established after casts taken of their hands had been analyzed the method Is expected to prove particularly ticul arly valuable in cases of questionable suicide |