Police make arrest in 1998 rape of girl

Police have arrested a man they believe is responsible for the 1998 rape of a 15-year-old girl, a development they said was made possible by advances in DNA technology.

The suspect, Calvin Gadson, 33, of the 700 block of North 43d Street, was arrested Jan. 4 on charges of rape, involuntary deviant sexual intercourse, unlawful imprisonment, aggravated assault, and related charges.

Though Gadson's DNA was collected at the time of the attack, it remained unidentified for years, stored in a laboratory, Philadelphia Police Capt. John Darby, commanding officer of the Special Victims Unit, said Tuesday.

Gadson's DNA sample was one of many samples that lab workers recently reanalyzed using a new set of identifying markers that were not previously available.

At some point during the almost 12 years since the rape, police said, Gadson submitted a DNA sample to police after an arrest for an unrelated crime. In July, forensic scientists found that Gadson's genetic material matched the sample collected in the 1998 attack, Darby said.

"I think the message is clear," Darby said. "These offenders never go off our radar screen. We never forget."

The victim, Darby said, "was obviously elated that we had not forgotten her."

Due to the passage of time, the DNA may be a stronger piece of the puzzle than the victim's own eyewitness account, Darby said. The victim could not identify her attacker in a recent photo array, for instance.

"The beauty of this technology is that, in a case like this, we don't have to be fully dependent on a witness account," Darby said.

Gadson has a lengthy criminal record, including a stint in prison after he pleaded guilty to robbery in 1999. He has also pleaded guilty to theft and criminal conspiracy, records show.

He has been accused of assault in past years, and was charged with aggravated indecent assault in 2005. That charge was later withdrawn.

The rape took place around midnight on Feb. 1, 1998, police said. The victim and her boyfriend were walking near 20th and Sedgley Streets when two men approached, brandishing guns.

The men each raped the girl while restraining her boyfriend at gunpoint, then robbed them and fled.

Police are still searching for the second suspect, Darby said.

Gadson's first DNA sample was collected at the hospital where the victim was taken after the attack, police said. There, it was classified as an unknown profile.

In 2003, police still had no ideas as to the rapist's identity. Concerned that the statute of limitations might hamper an arrest in the case, authorities acquired a "John Doe" arrest warrant that would allow for prosecution of the person whose DNA matched the sample on file.

In the meantime, Gadson submitted DNA to the police after one of his arrests. The genetic material that was connected to the 1998 rape had not been analyzed using up-to-date markers, so it was not an automatic match.

Authorities would not comment on exactly when Gadson's original DNA sample was analyzed for the second time, using a new set of markers. But last July, the state police found that Gadson's sample matched that of the one that was collected after the 1998 rape.

"Just like that, he went from being an unknown person to a name," Darby said.

In October, police went to Gadson's home and collected a DNA swab from him to ensure that it matched the earlier samples. In December, the tests confirmed the match.

Forensic lab scientists are continuing to reanalyze old DNA samples in hopes of making future matches, Lt. Tom McDevitt of the Special Victims Unit said.

"We may not come to you one, two, three years later," McDevitt said. "But sooner or later, we'll come to you."