What Are Some Advantages and Disadvantages of Using DNA Analysis to Aid Law Enforcement in Crime?

What Are Some Advantages and Disadvantages of Using DNA Analysis to Aid Law Enforcement in Crime
••• stevanovicigor/iStock/GettyImages

In little more than two decades, DNA profiling has become one of the most valuable tools in forensic science. By comparing highly variable regions of the genome in DNA from a sample with DNA from a crime scene, detectives can help prove the culprit's guilt--or establish innocence. Despite its utility in law enforcement, however, some applications of DNA have proven controversial.


The great advantage of DNA profiling lies in its specificity. Even relatively minute quantities of DNA at a crime scene can yield sufficient material for analysis. Forensic scientists typically compare at least 13 markers from the DNA in two samples. In a test with 13 markers, the probability that any two individuals would have identical profiles is estimated to be below 1 in 10 billion. Consequently, when specimens are collected properly and the procedure is performed correctly, DNA profiling is an extremely accurate way to compare a suspect's DNA with crime scene specimens.


DNA evidence is only one of many types of evidence jurors should take into account when considering a case. TV shows like "CSI" may have popularized forensic science to the point where some jurors have unrealistic expectations of DNA analysis and accord it more weight than other types of evidence. This phenomenon is sometimes called the "CSI effect." Maintaining DNA databanks can help police identify criminals, but it can also pose ethical quandaries when authorities keep samples from people who have never been accused of any crime. DNA dragnets, operations where police collect samples from a large number of people in a geographic region to find a culprit, have proven especially controversial.


It's important to remember that DNA analysis, like any other technique in forensic science, is susceptible to human error. Contamination during specimen collection or analysis can dramatically decrease its accuracy and reliability. As a general rule, DNA evidence is more useful in excluding suspects than in proving guilt. The Innocence Project at the New York Benjamin N. Cardozo School of Law has successfully established the innocence of more than 100 wrongfully convicted inmates through DNA profiling and other types of evidence.

Related Articles

Types of Forensic Tests
The Importance of Studying Human DNA Genetics
List of Forensics Techniques
Pros & Cons of Forensic Science
What Kind of Equipment Is Used to Analyze DNA?
What Makes DNA Fingerprinting Unique?
Forensic Science Projects for High School Students
The Role of Taq Polymerase in PCR
Restriction Enzymes Used in Forensic Science
Interesting Facts About DNA Fingerprinting
Sources of Error in Gel Electrophoresis
What Are the Differences Between PCR and Cloning?
Advantages & Disadvantages of Finding Variance
What Is the Next Step if an Experiment Fails to Confirm...
The Difference Between Gene Sequencing and DNA Fingerprints
What Is Forensic Botany?
When Was DNA Testing First Used?
What are Specific Biotechnology Applications for DNA...
What Are the 8 Steps in Scientific Research?
How to Calculate the Coefficient of Variation