Dennis Maher Case Study
When the pants were collected they could have been taken to a lab, and the area that presumed to have blood upon it could have been tested to see if it was in fact blood or another substance. In 1901, Joseph H Kastle developed a presumptive test for detecting blood by using the chemical phenothalin. While in 1903 E. Meyer discovered that blood triggered a reaction between hemoglobin and hydrogen peroxide (lecture). With these two discoveries the Kastle-Meyer Test, the most known presumptive test for blood identification, was created. The Kastle-Meyer test involved the usage of hydrogen peroxide, and the chemical phenothalin. When phenothalin and hydrogen peroxide are mixed with blood and a reduction occurs. This is because the heme group located within a red blood cell breaks down the hydrogen peroxide into water and oxygen The oxygen wants to gain an electron along with hemoglobin within blood and the phenothalin will give or lose an electron (forensic biology). When this occurs the phenothalin becomes phenothalein and a color is produced. This color in this reaction happens to be pink.
Another test that determines the presence of blood could be the Takayama Crystal Test. This confirmatory test for the presence of blood was created in the year 1912 by a man named Maseo Takayama (lecture). In this test a chemical called pyridine is used. The reaction of pyridine with hemoglobin produces hemochromagen, also referred to as pyridine ferriprotoporphyin, crystals which are salmon colored. If the stain in the Maher case passed the Kastle-Meyer Test and Takayama Crystal Test it could have gone to further testing to possibly producing results that could have exonerated Dennis Maher from one of the