Serology and Its Applications in Criminal Investigation

Serology is yet another aspect of forensic science that has been exceedingly useful in solving crimes and homicides. The first breakthrough in serology came in 1875 with the discovery that there are several different types of blood. In 1901, an Austrian biologist named Karl Landsteiner devised the modern blood-grouping system that we still use today. He noted that when he isolated the serum from red blood cells and mixed the serum with blood cells from multiple individuals, two different reactions occurred: sometimes the serum attracted the blood cells and other times it repelled them. These two different types of blood were named A and B. It was not long before Landsteiner discovered a third type that did not react in the same manner as A or B; it exhibited some characteristics of both. This group was originally named C, but later became known as O.

Approximately one year later, an assistant made the discovery that there was yet another type of blood that did not correlate with either A or B; this fourth group was called AB. In the 1920s, Landsteiner conducted an experiment by injecting the blood of a human being into a rabbit and discovered yet another grouping system that consisted of three types: M, N and MN. For his pioneer work in the area of serology, Landsteiner was awarded the Nobel Prize in 1930. A decade later, he discovered the Rhesus factor.

1949 brought about the next landmark discovery in serology. It was that year that two scientists noted the structural differences in the nuclei of female cells. This exclusively female trait was named the Barr Body and is explicable by the chromosomal differences between males and females.

The Application of Serology in Criminal Investigations:

These developments have proven to be extremely helpful in various areas, one of which is criminology. Because of these advances, modern detectives are able to use a Kastle-Meyer test to determine whether or not a sample is blood. The sample is mixed with phenolphthalein, a substance that will turn pink when it comes into contact with even the smallest amount of blood. Once the sample is confirmed to be blood, a second test (the precipitin test) is used to determine whether the blood is that of a human or an animal. After the blood is discovered to be of human origin, it can be examined to determine the sex and blood type of its owner.

Case Study: Ludwig Tessnow:

July 1, 1901- On the island of Rugen just off the northern coast of Germany, Hermann Stubbe, 8, and Peter Stubbe, 6, set out to play. Little did they know when they left their home on that fateful day that they would never return again. The hours passed and the young brothers did not return. Their family grew immensely concerned and a search party was organized the following morning. Several of the searchers stumbled upon dismembered body parts scattered among the woods. They followed the trail and made a macabre discovery: the eviscerated bodies of the two little boys.

A witness reported seeing a man by the name of Ludwig Tessnow conversing with the children on the day of their disappearence. Tessnow was a local carpenter who lived in the neighboring town of Baabe. He was interrogated by the police and claimed to have no knowledge of or involvement in the deaths of the two boys. As per the protocol of the time, Tessnow's home was searched. Upon searching the quarters, the police discovered several articles of clothing and shoes that were covered in dark stains. The man had a viable explanation: he claimed that the stains were from wood dye, a substance commonly used in his profession.

For some reason unbeknownst to him, Johann Schmidt (the examining magistrate) was very suspicious of Tessnow. Upon doing a background check, some disturbing information was uncovered. Three years prior, two young girls had been found disemboweled in the wooded area by their home. A man was seen lurking in the area where the bodies were discovered. His clothes were riddled with dark stains and he was detained and questioned by police officers. His name was Ludwig Tessnow and he claimed that the stains on his clothes were from wood dye. The officers accepted his explanation and Tessnow was not further investigated.

The grisly discovery prompted Schmidt and Ernst Hubschmann (the local prosecutor) to keep investigating Tessnow. Someone reported seeing a strange man fleeing from his meadow just a couple of weeks before the Stubbe murders. He went to investigate why the man was on his property and discovered the slain bodies of seven of his sheep. They were not just killed, but also horribly mutilated, suggesting the work of a psychopath. The dissected body parts had been scattered throughout the meadow. When asked to select the culprit out of a lineup, the man identified Ludwig Tessnow.

Tessnow was questioned again and still maintained his original story. All of the evidence against Tessnow was circumstantial and not adequate to hold him in custody. The authorities had to produce concrete evidence and fast. The prosecutor recalled hearing of a biologist who had developed a technique for distinguishing blood from other fluids as well as differentiating between animal and human blood.

The scientist's name was Professor Paul Uhlenhuth. His methods were more complicated than the modern ones used today, but effective and accurate nonetheless. After examining several articles of Tessnow's clothing and conducting various tests, he discovered that some of the stains were made by wood dye, but seventeen traces of human blood were also found. In addition, one of his jackets was stained with sheep's blood.

Tessnow was executed in 1904 at Greifswald Prison. Due to his feasible explanations, Tessnow was once overlooked in the murder of two young girls. Thanks to the intuition of the magistrate, the quick thinking of the prosecutor and the brilliant research of a biologist, a repeat of the error was evaded.