CHARLOTTESVILLE, VA. ? Steven Turner wondered who officers were looking for when a police van pulled up as he was riding his bicycle around dusk in his neighborhood near the University of Virginia.

It turned out police were looking for him, in response to a call about “a suspicious person riding a bike.”

The U.Va. graduate student had become the latest target of a DNA dragnet for a serial rapist. In a practice decried as racist, police have stopped nearly 200 black men to ask them for cheek-swab tissue samples.

Turner, 27, said he refused to give the officers a cheek swab that August night, then refused again when police showed up at his home seven months later, because he felt his rights were being violated.

“The question was not my guilt or innocence,” Turner said. “I know where my DNA has been.”

Police began stopping black men for DNA tests in November 2002, then stepped up the program last year after a victim got a good look at the rapist and described him as a 6-foot black man in his early 20s with an athletic build and unnaturally white, bulging eyes. The rapist is being sought for six attacks in the area between 1997 and 2003.

After black community leaders complained to Police Chief Timothy J. Longo that the testing amounted to racial profiling, Longo agreed in mid-April to place limits on the tests.

Police can no longer request cheek swabs from black men simply because they look suspicious or resemble a police sketch of the rapist. Officers now must notify a supervisor first, then inform the men stopped that they do not have to give a sample. If the men refuse, the officers will need to get a court order.

Of the 197 black men who had been stopped by police and asked to give a sample, 187 complied and all were cleared.

Steven Turner, a graduate student at the University of Virginia, is shown in this April 12 photo at the university in Charlottesville, Va. Turner was asked twice by Charlottesville police to submit a DNA sample as part of a dragnet for a serial rapist. He refused both times.

After police showed up at Turner’s home in March, again requesting a sample, he contacted Rick Turner, U.Va.’s dean of black studies, who put together a community forum after receiving other complaints .

“The African-American men in this community had to tell their stories about the humiliation they felt,” said Rick Turner, who is not related to Steven Turner.

Not everyone has objected to the testing. The officers “were just doing their job,” said Gary Spry, a black barbecue shop owner who has not been stopped by police.

Kent Willis, executive director of the American Civil Liberties Union of Virginia, says it is unlikely the DNA dragnet will catch the rapist. “DNA dragnets are ineffective and a waste of police resources,” he said. “What they tend to be is a way for police to demonstrate to the public that they are doing something, that they are taking steps to solve the crime.”