In the twenty-first century, we rely heavily on DNA. Law enforcement officials use it to catch criminals. Families use it to discover their ancestry. Parents use it to determine if their children may be at risk for a certain disability.

But what if DNA was wrong?

As shocking as that may seem, it is a possibility that many may not have considered yet. Here I present the case of Lydia Fairchild before delving into the concern for law enforcement and writers.

Lydia Fairchild was pregnant with her third child when she separated from her then-husband, Jamie Townsend. In 2002, she applied for enforcement of child support as she had custody of the children following their separation. There is a DNA requirement for this to prove that they are the parents of the kids.

Shockingly, DNA showed that Jamie Townsend was the father but Lydia was not the mother. How was this possible? She had given birth to both of her children and was clearly carrying a third. She had Jamie to support her statements and had their birth certificates as proof. There was no way she wasn’t their mother.

However, Lydia was now on the hook for a crime, either a surrogacy scam or claiming benefits for someone else’s child. The children’s birth certificates were called into question. So, the judge ordered an observer to be present during the birth of Lydia and Jamie’s third child. In addition, the baby’s DNA was to be tested immediately after the birth.

Lydia soon went into labor and had what was probably the most uncomfortable birthing experience I could imagine. The observer was present. DNA was taken. Yet, the results were the same.

Luckily, Lydia Fairchild had an amazing defense attorney who was open to crazy ideas. They read an article about a chimeric woman and suggested the possibility to the court.

Chimerism is a medical condition where a single organism (human or other) has cells with more than one genotype. With humans, this means that the individual’s blood cells can have different blood types and/or DNA. Generally, this is not visible and most people show no signs or symptoms of the condition. That said, there are some people who have hyper- or hypo-pigmentation of their skin or different colored eyes, which would show obvious signs of chimerism.

Lydia Fairchild was one of the former cases. She did not have different colored eyes or pigmentation issues. She did, however, have two sets of DNA in her body.

To test this theory, DNA samples were taken from Lydia’s mother, the children’s grandmother, to test against her children. When the DNA came back, it matched as one would expect of a grandmother figure. Additional testing found that the DNA in Lydia's skin and hair did not match her children's, like the blood taken from her body for traditional DNA tests. However, the DNA from a cervical smear test did match that of her children. Essentially, she carries a different set of DNA in her uterus compared to the rest of her body.

Lydia Fairchild’s case is only an example of the chaos that can ensue in the justice system for someone who has chimerism. What happens if a human chimera commits a crime?