ALABAMA - Why were roadblocks in St. Clair and Bibb counties asking for blood and DNA samples this weekend?

OFF THE WIRE
PELL CITY, Alabama -- St. Clair and Bibb county authorities are confirming there were roadblocks at several locations in their counties Friday and Saturday asking for blood and DNA samples. However, the samples were voluntary and motorists were paid for them as part of a study, they said.
According to Lt. Freddie Turrentine of the St. Clair County Sheriff's Department, it isn't the first time such roadblocks have occurred in the area.
"They were here in 2007," said Turrentine, the supervisor in charge of the roadblocks, which took place in several locations in St. Clair County Friday night, early Saturday morning and Saturday night and early Sunday morning. "It's just with social media and Facebook now, word of it has just exploded."
Turrentine said the roadblocks were part of a study conducted by the Pacific Institute for Research and Evaluation, working with the National Highway Safety Administration. St. Clair County was asked to participate by the Alabama Department of Economic and Community Affairs because it had worked with the group six years ago.
Sheriff Keith Hannah in Bibb County said they too had previously participated in the study.
Here's how the road blocks worked, Turrentine said:
Off-duty St. Clair County deputies stopped cars at random at road block areas. The road blocks were marked with signs stating it was a paid survey. Cars stopped were asked for voluntary cooperation. Drivers were offered $10 for a mouth swab, and $50 for a blood test. If they refused, they were free to drive away.

[ POLL: Would you voluntarily submit DNA, blood sample for government study at roadblock? ] 

Road blocks took place Friday at the New London Fire Department, Alabama 34 in Pell City near the old Dan's Car Wash, U.S. 231 at Alabama 144, at White's Chapel Parkway and Moody Crossroads in Moody. In Bibb County, the road blocks took place in five areas in the county on Friday night through early Sunday morning.
If drivers participated, they were directed to an area where someone from the group carrying out the study took the samples, he said.
"It was completely voluntary," Turrentine said, saying reports that people were detained if they did not cooperate were untrue. "If they didn't want to take part, they could drive off."
The samples were anonymous, he said.
Poll: Would you voluntarily submit DNA, blood sample for government study at roadblock?
"They were taking the samples in other parts of the country," he said. "They want to find out of all the people surveyed, how many people were driving with alcohol in their system, or prescription drugs, things like that."
This will be the only time this year the survey takes place in St. Clair County, he said.
Turrentine, who was at one of the roadblocks, said the group carrying out the study would ask for a certain number of volunteers. Deputies would stop drivers until that number of drivers needed agreed to the survey. Then they let cars pass while the samples were taken.
"We would have a lot who didn't want to take part, especially at night," he said. "But then we'd have a few that when we'd tell they could make $60 bucks, they said, 'What do I need to do?'"
Update: Feds, state officials comment on road blocks
If you were stopped in one of the roadblocks, or took part, and would like to talk, email eastalabama@al.com.
Here's a link to a 2007 study which used Bibb County.