Deoxyribonucleic acid (DNA) is the body’s unique biological code which contains the genetic design of each living organism. Each living organism contains an individual DNA profile. DNA stores information about the individual organism. Since a person’s DNA is individualized specifically to that person it can be an identifier in forensic science or cases or paternity. Lately DNA is becoming a household word often heard on the news regarding the arrest, conviction, or release of a person involved in a crime.
Back in the early 50’s James D. Watson and Francis H.C. Crick, were the first biochemists to propose a model for the structure of DNA. Their work in the structure and identification of DNA has opened up a whole new world for science and a Nobel Prize for both men in 1962. In the present their work brings to the forefront of crime a way to identify parents of children and criminals.
Identical twins form when one fertilized egg divides into halves. Identical twins are the only people who have the same DNA. Fraternal twins form when two eggs, fertilized by two different sperm. Fraternal twins have their own individual DNA. The DNA of a fraternal twin is no closer to matching the DNA of the other fraternal twin than any other sibling DNA would match as most siblings and fraternal twins share about 50% of their genes.
Although identical twins have the same DNA genotype, or internal cell DNA, their DNA has different phenotypes or external ways the DNA shows up. In other words, identical twins have individual fingerprints. So, if a serial rapist has an identical twin, law enforcement must find more evidence to use for conviction. A simple fingerprint however can and will distinguish identical twins.
Federal Law requires all convicted felons provide DNA to the Nation’s Combined DNA Index System (CODIS). CODIS essentially takes the best of forensic science and computer technology to compare DNA samples of unsolved violent crimes nationwide. If the DNA evidence collected from a crime scene or crime victim was entered into CODIS, and later a felon’s DNA is entered and it matches law enforcement is notified.
This same simple DNA sample for CODIS is exactly what led to the arrest of a serial rapist in a crime over a decade old in Missouri. The sexual assaults happened from 1996 through 1998. As far as law enforcement knows four girls were assaulted. All the girls were assaulted in their or a home of a friend, while parents or adults slept in rooms other bedrooms of the homes. The girls were age 11 to 17 at the time they were raped.
Charles Joseph Steffani was 54, when he received his sentence of 20 years in prison. This sentence given for sexual assaults committed in June 2005 in both the St. Louis and St. Charles counties of Missouri. What happened next is exactly what CODIS is designed to have happen. Steffani, now a felon, had to give DNA sample for CODIS and when he did and it was tested it gave a “hit” that he was a match for the rapes of the four young women in Missouri.
The only downfall is CODIS has caused a backlog in Missouri’s state crime lab as in most states, and this backlog prevented law enforcement officials from receiving the news of the match sooner. Law enforcement only learned last summer about the match with Steffani. Once officials learned there were several hits they began to compare notes among themselves and review old cold cases to see what fit and what did not fit and soon the cold cases heated up.
The first assault occurred when a man entered a home through an unlocked sliding glass door, and assaulted a17-year old in her bedroom, after pulling a pillow case over her head. The next night he entered another suburban home using a garage door opener from a car in a driveway. This time he assaulted a 12-year old, after pulling her shirt over her head. This was November 1996.
Then nothing, until April of 1998, when a 12-year old girl is assaulted while at a sleep over with two other girls. The rapist left all 3 girls with a “message from God”. He told the girls to go to church on Sunday and not to have sex until the girls were married. The last known attack occurred in June of 1998. Once more the man entered the girl’s home with a garage door opener he grabbed from a car in the driveway.
The prosecuting attorney’s office talked to all four survivors recently. How incredible to be able to tell these women that the monster who terrorized them has been identified and is in prison, thanks to the modern wonders of DNA. Now a decade later, the women could finally place a name and face to a childhood monster that crept out of the darkness so quietly a decade ago, Charles Joseph Steffani. A Grand Jury charged Steffani with 17 felonies. Those include multiple counts of forcible sodomy, sexual abuse, and one count of statutory sodomy and forcible rape for each woman.
There was a time unless a survivor could positively identify her attacker, there was no case. DNA technology can identify a rapist years, even decades later. Yes, technology is amazing. Yet, DNA is only as good as the person who collects and preserves the evidence. A crime scene once contaminated loses any DNA that is present.
Recently DNA from stamps attached to an envelope several decades old held clues to the identity of a serial killer who had mailed letters about the crimes he or she committed to a newspaper years earlier. A crime once considered unsolvable, before DNA was even considered as a tool in crime fighting; now one day may be able to identify a serial killer who has tormented a country. Currently any DNA evidence properly collected and preserved increases the chances of the case one day having a resolution, even if several more years down the line. DNA is just the beginning of what is to come in forensics, crime fighting and helping survivors bring closure.