Anniversary of First DNA Conviction

A noted doctor and a noted lawyer are sharing their memories of the first time DNA evidence was allowed in a criminal trial in Houston. That landmark trial happened 20 years ago this week, as Jim Bell reports.


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In 1988, Assistant D-A Attorney Rusty Hardin drew the job of prosecuting a man charged with raping several elderly women in the Heights. The homicide detective working the case had read a magazine article about Scotland Yard using DNA to convict a rapist in London, and he told Hardin DNA might work in the Houston case. Hardin, who’s now a well known defense attorney, agreed. He says matching the suspect’s DNA with DNA found at one of the crime scenes was the easy part. Getting it into evidence at the trial was harder, because the very idea was so new at that time.

“I think at that time DNA evidence had been admitted in only three states in the country.  And the overwhelming number of states had not allowed it in yet.”

Hardin says once he had the DNA match, he needed someone who could explain it to a jury, and he was referred to Dr. Tom Caskey of Baylor College of Medicine. Caskey is a nationally known DNA expert, and he’s a teacher, so that’s the approach Hardin used in the trial.

“What we decided among ourselves was look, you’re a teacher, in addition to everything else you do. I’ll put you up in front of an easel, and you just sort of explain the process. I’ll ask you one question, you answer that, and if it doesn’t make sense to me I’m gonna assume it’s not making sense to the jury, and I’ll follow up.  We’ll just do it like a class.”

Dr. Tom Caskey says DNA matching is taken for granted these days, but not in 1988.

“We were fighting an uphill battle to even get this evidence into the courts. The courts were very disbelieving, and they were challenged by of course the defense lawyers.”

Caskey first had to explain how DNA works to the judge with the jury out of the room, and then explain it again to the jury in language they could understand, with prosecutor Hardin asking questions like a curious layman. The jury understood, found the rapist guilty and sentenced him to life in prison. DNA matching is now used almost everywhere to prove guilt and innocence, and Caskey says he’s proud of his contribution to that.

“Although many of the medical discoveries that I have made I think are far more important, this one really impacted society, and it impacted the way in which DNA was used by society to get the truth.”

Jim Bell, KUHF, Houston Public Radio News.

To learn more, visit the University of Texas Health Science Center Web site.

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