The rape suspect, court papers said, was identified by a longtime friend who said they committed the crime together. The suspect’s DNA was tied to the crime. But prosecutors hoping to present an airtight case had a concern: The suspect, Dwayne McNair, has an identical twin, meaning the DNA testing pointed not to one person, but two.
It was a twist worthy of a crime novel, but one that has cropped up from time to time in cases both in the United States and Europe, including an earlier one in Boston. Because monozygotic twins, the scientific name for identical twins, come from a single fertilized egg — the same genetic material — they cannot be distinguished by conventional DNA testing, confounding prosecutors who might otherwise be able to build a solid case.
Prosecutors here are hoping that McNair’s case will be a breakthrough for criminal cases involving identical twins. On Monday, McNair pleaded not guilty to eight counts of aggravated rape and two counts of armed robbery in two separate attacks he is accused of committing in 2004.
To make their case in court, prosecutors want to present evidence from a cutting-edge DNA test, performed by a European company, that they say shows that McNair, and not his twin brother, Dwight, committed the attacks.
“We’ll be the first jurisdiction in the U.S. to bring this evidence forward, if it is acceptable,” said Daniel F. Conley, the Suffolk County district attorney, after McNair was taken into custody on Monday.
Read the full, original story: New DNA test sought in identical twin’s rape case