Surveillance video shows a man police say is a serial rapist who targets sorority sisters.
All his victims are members of the Delta Sigma Theta sorority, one of the most popular on campuses across America.
The predominantly black sorority has a host of superstar alumnae including Natalie Cole, Roberta Flack, and Aretha Franklin.
Delta Sigma Theta sisters are proud of those three Greek letters which indicate their membership in one of the largest sororities in the world. But police have no idea what is leading a rapist to target women connected with this famous sorority.
Delta Sigma Theta is warning members who live in the Dallas area not to wear clothing, or carry key chains or display bumper stickers or license plate holders which would reveal their link to the sorority.
"One has to believe he has some connection to that sorority, some anger towards that sorority, so that he actually fantasizes about getting these particular women," said Criminal profiler Pat Brown.
Some men do become obsessed with sorority sisters. Scientist Bruce Ivins, suspected of mailing anthrax laced letters in 2001, developed a lifelong obsessed with Kappa Kappa Gamma girls after he was rejected by a sister when he was a college student.
Four of his letters were dropped off at a mailbox near the Kappa Kappa Gamma sorority at Princeton University. He killed himself in 2008.
And in the 2009 movie, Sorority Row, sorority sisters are targeted by a serial killer.
Now one man's sorority fantasy has become a horrific reality.
"He's got some kind of grudge against this group of women," said Brown.