Police seeing double in rape case involving identical twins
By Matthew Gilbert
(Court TV) -- Identical twins not only look exactly alike, they have the same DNA. So what happens when that DNA is evidence in a sexual assault case?
Authorities in Grand Rapids, Michigan, are dealing with just that dilemma in the case of a Kendall College of Art and Design female student who was raped on November 23, 1999.
The woman, now 26, was attacked from behind, pushed against a car and sexually assaulted. She reported the assault to police and underwent a sexual assault examination, and doctors sent the sperm found to a state crime laboratory.
With no fingerprints at the scene and the victim unable to give detectives a description of her attacker, the case was at a standstill. But three months ago, the state crime lab matched the DNA found on the rape victim to that of Jerome Cooper, who has been in prison since 2002 on an unrelated home invasion conviction. Like all defendants facing felony charges in Michigan, Cooper had to submit a DNA sample for the state database.
The match seemed to solve the case until a background check on Cooper indicated he has a twin brother, Tyrone. To add to the intrigue, authorities were unsure whether Jerome and Tyrone Cooper were fraternal or identical twins.
Fraternal twins, which account for about two-thirds of twin pregnancies, have different DNA because they come from two different eggs being fertilized at the same time.
"The DNA profiles of fraternal twins differ as much as DNA profiles of any other pair of siblings," said Dan Krane, an associate biology professor at Wright State University in Dayton, Ohio.
Identical twins, however, have the same DNA because they come from one egg that split in half.
Authorities issued a felony warrant for Tyrone Cooper for failing to update his address on the sex offender registry. Tyrone and Jerome Cooper both have a record for sexual assault after pleading no contest to sexually assaulting a 10-year-old girl in 1991 and a 12-year-old girl in 1998, respectively.
Tyrone Cooper was arrested May 20 at his girlfriend's apartment in Kentwood, Michigan. DNA testing revealed that the Cooper twins were identical.
Police will now have to use other means, including investigating the brothers' alibis, to solve the case.
Jerome Cooper told police he was in jail when the rape occurred. However, Grand Rapids police Sgt. Timothy called Cooper's alibi "unsubstantiated." Court records indicate that Cooper was out on bail at the time of the incident.
Calls to Tyrone Cooper's attorney, Frank Carrozza, were not returned.
Williams said authorities will focus much of their energy into looking for eyewitnesses. They will also see if the DNA samples can be further analyzed.
"We are in the process of consulting with half a dozen research labs across the country to see what else can be done," said Williams.