Two decades after the bodies of Colleen McNamee, 20, and Rita Tangredi, 31, were found strew near the Long Island Expressway, there is a break in their unsolved murders. John Bittrolff, a married carpenter and father of two, was arrested in July for allegeding murdering the women. He was possibly involved in the death of a third, Sandra Costilla. Both McNamee and Tangredi were found naked with their bodies posed the same way, and they were so badly beaten that their brain tissue was exposed. The arrest was made thanks to DNA evidence. When police arrested Bittrolff’s brother in 2012, they took a DNA sample that partially matched the semen found on the women’s bodies and eventually traced it to Bittrolff himself. “It was the miracle of DNA which allowed us to arrest him and then prosecute him,” Suffolk County district attorney Thomas J. Spota said.