DNA Tests Fail to Distinguish Between Twin Rape Suspects

Grand Rapids - Twin brothers, both suspects in a rape case. But, who did it? That's the question facing Grand Rapids Police. It's a question they hoped DNA technology could solve. But, today's technology isn't giving police an answer.

Police say either Jerome or Tyrone Cooper raped a woman in November of 1999, near Fulton and Jefferson in Grand Rapids. Sgt. Tim Williams of the Grand Rapids Police Department says.According to the DNA, one of them is responsible for this assault.The problem is, Jerome and Tyrone Cooper are identical twins, with identical DNA. So, police don't know which twin is responsible for the rape.

That's where Orchid Cellmark came in. The bio-science company tested the Cooper brother's DNA. Dr. Robert Giles of Orchid Cellmark says,What we were looking for were very minute differences, genetic differences that might occur between identical twins.These are differences or mutations that may have come about, since the time when the egg split, creating twins. But, Giles says,Unfortunately, what we have found is that if these minute differences do exist, we have not been able to pinpoint them with the technology that we currently have available. Technology has come a long way. Scientists used to be able to test just a few hundred characteristics of DNA. For the Cooper brothers, Orchid Cellmark checked about 100,000 DNA characteristics. But, scientists still did not find any differences.

But, the company is not giving up, just putting efforts on hold. Orchid Cellmark says as quickly as technology is improving, they could be able to check even more DNA characteristics in just a few months.

So, police still hope the DNA will point a finger at one of the Cooper brothers. Sgt. Williams says.They obviously are on notice that we know that one of them is responsible. So, it's not going to be forgotten.There is no statute of limitations in this sexual assault case.

The Cooper brothers, will wait for any future DNA results behind bars. Both men are in prison on separate, unrelated charges. But, both are up for parole in 2006.