Can You Cheat on a DNA Paternity Test?

By Kevin Camilleri 

DNA Paternity Testing is now the most widely used method of confirming a biological relationship between an alleged parent and their siblings. There are essentially two types of tests you can perform. There is the 'Court Admissible' Test whereby the collection of the samples is performed through a controlled chain-of-custody procedure with a third party to act as a witness and verify the authenticity of the samples. Then there is also the 'At-Home' DNA test whereby a DNA testing kit will be sent to you and you will be responsible for collecting your own samples. The At-Home test is also commonly known as Peace of Mind Testing.

Due to the nature of collecting the samples, the legal test of course provides an almost cheat proof system if a neutral and qualified third party witness is used.

However for the home DNA test, since the parties are responsible for collecting their own samples, this gives rise to the opportunity to cheat on the test. This can be done by submitting someone else's sample which will inevitably lead to a negative result. This possibility has led some to question the reliability of the at-home tests.

Accuracy of the DNA Paternity Test

From a scientific point of view, the accuracy of these tests is now almost a given. When the father, mother and child participate in the paternity test, a properly accredited and experienced DNA testing laboratory will provide a probability of paternity in excess of 99.999% thereby confirming the biological relationship, or alternatively issue a probability of paternity of 0%, thereby confirming with 100% accuracy the exclusion of the alleged father.

The laboratory of course cannot know if the samples provided are of the correct person (s). In fact, it is quite normal for a DNA test result to clearly state that the samples have not been verified and hence the report cannot be used in a court of law.

Only in cases where the samples submitted are of the wrong sex will the laboratory question the samples, since by testing the Amelogenin gene (nowadays a standard part of a DNA paternity test), this will confirm the sex of the donor. Also submitting the sample of an animal (e.g. swabbing you dog) will also be picked up by the laboratory as it will not be possible to conclude the test.

In addition, once the samples are processed, the laboratory will issue a DNA profile that is unique to the individual. Whilst the result will of course be erroneous, in the event the other party manages to obtain the correct sample, the new profile can be easily matched to the old profile to confirm if they are similar. Having said all this, it is still obvious that it is possible to cheat on a home paternity test by submitting another human's sample and of the same sex.

What should I do if I think my partner will cheat on the DNA Test?

Therefore if you are suspicious that your partner might cheat on the test you have the following options:

1. Perform the swabbing procedure in the presence of all parties and make sure to seal and send yourself the samples to the laboratory.

2. If it is not possible to be present at the same time or location have the samples taken in front of a neutral third party (i.e.) (a lawyer or doctor preferable) that will act as an independent witness to the collection. If the test is not being done for legal purposes then the third party witness will not need to sign any official documents for the laboratory to issue a 'Legal' result. He will just guarantee peace of mind to all the parties.

3. Order a 'Court Admissible' test and follow the chain of custody procedure required for the collection of the samples.

4. If the other party refuses to provide a sample under any of the above scenarios, proceed through official legal channels to 'force' the other party to participate in the test. This is of course the most expensive and time consuming process and should be entered into as a last resort. In situations such as this, we strongly recommend obtaining legal advice. 

Do Clients Often Cheat?

 In my extensive experience in the field of DNA testing, it is very infrequent that a person will try to cheat on a paternity test when supplying his own sample. Most clients are bona fide clients who simply want to find out the truth. Also in cases where the other party suspects possible foul play, they will take measures as per above. However, in the limited cases where there has been an attempt to cheat, the negative result were always challenged by (most cases) the Mother who eventually managed to obtain the correct sample for re-testing.

Other examples of cheating include Mothers who know that it is highly likely that the man being tested is NOT the biological Father and they will try to contaminate the child's swab with there own DNA, as they think this will provide a negative result without the laboratory noticing. However, since the laboratory will pick up this contamination, re-testing will be required.

In conclusion, whilst one may try to fool or cheat on a paternity test, eventually the truth more often than not comes out either through scientific methods detecting the tampering or through the process of obtaining supervised re-sampling.