Mandatory DNA Sampling in a Criminal Investigation

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What is DNA Sampling or Testing?

DNA sampling or testing is used for the purpose of verifying the identity of an unknown person.  It is commonly used in criminal investigations for the purpose of identifying suspects to a crime.  DNA sampling is also common in other areas of law, such as paternity testing.

DNA samples work by extracting a sample of DNA from the suspect under investigation.  Samples may be obtained by a variety of methods, including fingerprint samples, “swab” samples obtained from inside the cheek, or bodily fluid samples (such as blood).  The DNA samples are taken directly from the person in question. 

The samples are then compared to DNA samples obtained from other sources of evidence, such as a blood stain or a strand of hair found at the crime scene.  If the samples match, it may provide evidence of guilt during prosecution.  The reliability of DNA testing is subject to debate, though it is generally believed to be highly accurate.

Is DNA testing Mandatory in a Criminal Investigation?

Currently, DNA collection is mandatory in all fifty states for certain felony crimes, mostly sexual assaults and homicides.  47 states also require DNA samples to be taken from all convicted felons.  Also, some states have also implemented mandatory DNA testing for juvenile offenders.

Some states have even gone so far as to require mandatory DNA testing for all suspects who have been arrested.  For example, in California, all suspects who have been arrested for a felony must submit to DNA testing.  Some states may also require DNA sampling for certain misdemeanor crimes.

Because of the fact that suspects may be required to submit to DNA testing even before they are found guilty, the constitutionality of DNA testing is often subject to debate.  Many have also felt that mandatory DNA testing is an invasion of privacy, especially the types of sampling that require some bodily intrusion (such as drawing blood).  Therefore the DNA testing requirements will vary according to state.    

Also, although DNA testing is usually used to prosecute suspects, DNA testing may sometimes be used for the purpose of defense and exoneration.  For example, the defendant may offer the DNA sample as evidence that they did not commit the crime. 

What is the Combined DNA Index System (CODIS)?

The Combined DNA Index System, also known as “CODIS”, is a type of DNA database.  It uses computer systems to store DNA profiles that are generated by crime laboratories. 

The DNA profiles may be connected with either federal, state, or local criminal violations.  CODIS provides authorities with the ability to browse the database in order to identify suspects to a crime.  Thus, if a person has previously submitted to DNA testing, the record of the DNA profile is likely being held in the CODIS system.  

Can I have my DNA profile removed from a DNA Database?

In some instances, a person may petition to have their DNA sample or profile removed from DNA identification databases.  This is usually allowed if the person has been cleared of criminal charges or is seeking to have their record expunged.

For example, a person who is in the process of expunging a conviction in Arizona may request to have their DNA profile removed from Arizona database systems.  The request to have DNA profiles removed may often be submitted simultaneously with the expungement petition. 

Do I need a Lawyer for issues with DNA Sampling?

The use of DNA sampling in a criminal investigation has been widely debated ever since its introduction to criminal procedures.  If you have issues regarding DNA sampling, you may wish to consult with a lawyer for advice.  A lawyer will be able to explain your rights to you according to the particular laws of your state.  Your attorney can also determine whether DNA testing is appropriate in your situation and whether it will serve to help your case. 

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Last Modified: 09-07-2012 11:21 AM PDT

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