DNA Profiling
Science has given crime labs new and powerful methods for identifying criminals. DNA profiling is one of the biggest breakthroughs ever made in forensic science.
Everyone's DNA is different. Each cell in a person’s body has a complete complement of their DNA. DNA profiling involves analyzing the DNA from any body cells a criminal leaves behind. One drop of saliva or a single hair is sufficient to profile a suspect’s identity to an accuracy of one in ten million.
When police send a DNA sample to the lab, a special enzyme is used to break strands of DNA into fragments. Then these are separated according to size. Each individual’s DNA breaks into pieces of different lengths and composition. Next, a gene probe tagged with radioactivity is washed over the fragments, and binds to specific places on them. A photograph identifies a pattern of dark bands where the gene probe has stuck to the fragments. The suspect’s DNA fragments are then compared with samples found at the crime scene.
DNA profiling has led to some spectacular convictions. As well, a significant number of convicted rapists has been exonerated using this procedure.
So next time you read about a conviction of a dangerous criminal, be thankful for the work of scientists whose research led to this powerful identification technique.
It seems that every few weeks we hear of another case of an important criminal investigation being solved by using DNA to identify the perpetrator. Some cases, years old now, are resulting in conviction of the criminal and resolution for the victim and his or her family members.
DNA profiling makes it significantly harder for apprehended suspects to escape. Of course a key is that it still often takes plain old-fashioned police work to track them down and arrest them, but once they are caught, convictions are much more likely.
It’s surprising how even the most careful lawbreaker inadvertently leaves bits of DNA behind at the crime scene - a bit of skin, a drop of blood, a hair or two. That’s all it takes to make a positive identification and place the offender at the scene, a key aspect of any criminal investigation.
It intrigues me that with all of the information about DNA profiling in the popular press, people still take chances on committing their crimes expecting to avoid detection. This is particularly true of rapists who leave significant DNA samples for police to work with.
Most of us are aware of desires to do whatever we can get away with to further our personal goals of pleasure, satisfaction, and significance. While we don’t always buckle to the temptation to act on those desires, no one can say that he or she has never caved in to the urge to go beyond the bounds of conscience, social proprieties, or divine ordinance.
Occasionally, wrong-doers are able to convince a jury of their innocence, though that is getting more difficult all the time. The fact is, though, when we come to the supreme moment of evaluation, we will not be able to trick the Judge, or lay the blame at someone else’s feet. Our identity and connection to the wrong we have done will be certain.
The good news is that, though because of our behaviour we already stand convicted (by God’s standards, if not social conventions, and personal conscience), the expected sentence is not inevitable. God has made a way for a full pardon to be granted to us. By dealing with our sin Himself, He makes it possible for us to experience total forgiveness.
David Humphreys and Ron Hughes
© August 2004
