Seek a Lawyer’s Advice Before Providing a DNA Sample

 It is common knowledge that law enforcement uses DNA analysis to investigate and solve crimes.  Prosecutors then use this DNA evidence at trial to convict the accused.   If you are charged with a crime and your case involves DNA evidence, it is important that you retain a lawyer who understands DNA evidence, including its limitations.  Having an experienced lawyer in this regard can assist you with challenging law enforcement requests for the production of your DNA, as well as the introduction of DNA evidence against you at trial.

What is DNA?

DNA is short for its true scientific name, ‘deoxyribonucleic acid.’  This self-replicating material is present in nearly all living organisms and is found within the nucleus of the millions of cells that comprise the human body.   DNA is unique to each individual, with the exception of identical twins, and is often referred to as the genetic blueprint.   Sources of DNA include bodily fluids such as blood, semen, and saliva; hair roots; and skin cells that are either shed from the body or contained in saliva.

Determining an individual’s DNA

To determine an individual’s DNA, lab analysts require a sample from one of the potential DNA sources.   From the sample, analysts use a combination of chemicals and technology to isolate specific cells comprising the sample, crack open the nucleus to the cells, and access the DNA material contained inside.  From this material, they extract a DNA profile, which is memorialized as a series of numbers. 

When law enforcement conducts DNA analysis for evidentiary purposes, police obtain and submit known DNA samples to a laboratory for DNA profile extraction and comparison against an unknown DNA profile developed from evidence found at a crime scene.  If there is a match between the known and unknown DNA profiles, this match is used by police to identify a suspect for purposes of making an arrest followed by a criminal prosecution.

All known DNA profiles collected by law enforcement are stored in a national database.  This resource is available to all law enforcement agencies across the country for purposes of investigating crimes.  If your DNA is obtained by law enforcement for any purpose, it is likely uploaded into and stored in this database.

Obtaining DNA samples

Police obtain DNA samples in various ways.  Many laws require that, upon conviction of a felony, the convicted offender must furnish a sample of his or her DNA to law enforcement.  These samples are uploaded into the national database.

Consensually providing a DNA sample

One common method police use to obtain a DNA sample is to simply ask a suspect under investigation to consensually provide a sample.  This sample is typically collected in a non-intrusive manner by swabbing the inside of the individual’s cheek with a buccal (cotton) swab to collect skin cells from inside the mouth and saliva.  An individual has no legal obligation to provide a DNA sample to the police.  However, police rely on intimidation, suspect fears and anxieties, and the overall coercive nature of the relationship between police and suspect to obtain DNA in this manner.  Many suspects are not educated about DNA science and, therefore, unwittingly provide their DNA samples to police without fully understanding the implications of their actions.

If a suspect agrees to provide a DNA sample, police will ask him or her to sign a consent form, voluntarily agreeing to provide the sample.  If a suspect chooses not to consent to provide a DNA sample, police cannot force the sample from him or use his denial against him.  The denial is not evidence.

Absence of consent

In the absence of consent, police are required to obtain a warrant to obtain a sample of your DNA.  If the police ask for your permission to collect a sample of your DNA, this means they do not have a warrant and likely do not have probable cause or grounds to successfully obtain one. 

In any event, if you are asked by police for a DNA sample, you should respectfully decline until you consult with a lawyer.  Speaking with a criminal defense lawyer who is experienced in handling DNA evidence will better enable you to make an informed choice about whether providing your DNA to police is in your best legal interests and the possible consequences of doing so.

DNA samples from items

Police also obtain DNA samples from items that you have contact with and leave behind.  Classic examples include:

• drinking implements such as cups, glasses, cans, bottles and straws; gum or candy you spit out
• used condoms discarded into the trash
• and cigarette butts, cigars or other smoking devices 

The possible items and locations where you leave behind your DNA are endless.  In addition to bodily fluids, DNA is also contained in skin cells.  The human body sheds countless skin cells each day as we engage in normal daily activities.  DNA may be left behind by simply touching an object or contact with an object and any part of the body.

Self-DNA kits

Self-DNA kits are now widely available for sale in drug stores and other retail outlets.   These popular kits have become commercially available to individuals seeking to learn of their ancestry or susceptibility to disease and illness.  A new trend has emerged in law enforcement where police obtain access to the commercial DNA databases comprised of known DNA profiles from self-test kits to compare to unknown DNA profiles developed from criminal investigations.  Because of this, individuals are cautioned about using these self-test kits.  By using a self-test kit, you may be unknowingly providing your genetic blueprint to the police, who, one day, may be unforeseeably investigating you for a crime.

Because of its accuracy, DNA evidence in criminal cases is a powerful weapon for the prosecution and is often impossible to overcome by the defense.  Most successful defenses seek to incorporate this almost irrefutable evidence, as opposed to challenging its reliability or admissibility.  There are some concerns regarding modern DNA analysis techniques.  Also, contamination of DNA samples can occur from the sample collection and handling.  While these arguments may always be made, DNA evidence – overall – is very challenging to refute or discredit.

 Contacting a Defense Attorney for legal advice

If you have been accused of or are under investigation for a crime, call the Law Office of John L. Calcagni, III today for a free consultation.  Attorney Calcagni is an experienced criminal trial attorney who understands the science of DNA.  He has successfully defended and won cases where DNA evidence was offered against his clients.  While DNA evidence may be powerful, winning your case, with the right attorney and best defense strategy, is always possible.