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Should Killers With a Violence Gene Get Lighter Sentences?
Anthony Blas Yepez killed a man. Is his DNA to blame?

In 2015, Anthony Blas Yepez was sentenced to more than 22 years in prison after killing George Ortiz, his girlfriend’s step-grandfather.
Three years prior, Yepez and his girlfriend were living with Ortiz when, according to testimony, Ortiz hit Yepez’s girlfriend in the face. Yepez says he isn’t sure what happened next but that he “must have blacked out.” When he came to, he was on top of Ortiz, who was bleeding and appeared to be dead. Yepez and his girlfriend then poured cooking oil on the victim, lit him on fire, and fled the scene in Ortiz’s car.
Now, Yepez’s lawyer, Helen Bennett, is seeking a retrial for her client — and she’s relying on an unusual argument: that Yepez is genetically inclined to act violently due to the “warrior gene.”
Specifically, Bennett is arguing that Yepez has low levels of the enzyme monoamine oxidase A (MAOA). Some research implies that people with low MAOA do not regulate chemicals in the brain properly, which can result in abnormal aggression. Later this year, the New Mexico Supreme Court is expected to review the case.
“Now is the time for courts to begin to analyze this intersection between science and law.”
According to Bennett, Yepez has low MAOA levels and suffered abuse in childhood. (Some evidence suggests that childhood trauma combined with low MAOA can lead to antisocial problems.)
“Under certain circumstances with people with a certain genetic makeup who have had experiences of abuse or trauma in their childhood, their free will can be overrun by this impulse to violence,” Bennett tells Medium.
It’s not the first time Bennett has attempted this argument for Yepez. In 2015, she tried to introduce the warrior gene theory into case evidence, but the judge at the time rejected it. Bennett is hoping for a second shot.
“Now is the time for courts to begin to analyze this intersection between science and law,” she says. “As science envelops and touches upon so many aspects of our society, it’s really incumbent upon the courts to engage in…