Tennessee Code Title 38. Prevention and Detection of Crime § 38-8-125

(a) “Human sample” means a cheek swab, blood or urine sample, saliva, hair or any other bodily fluid or exemplar from which the DNA of the donor may be derived and identified and for which a law enforcement officer would be required to seek a search warrant to obtain such sample.

(b) No state, county, municipal or metropolitan form of government law enforcement officer shall participate in, lend assistance to, or be present in any official capacity at any voluntary motor vehicle checkpoint or stop conducted by a private company or research group to collect a human sample from consenting motorists stopped at the checkpoint for research or statistical purposes.

(c) Subsection (b) is applicable regardless of whether the checkpoint is funded by federal grant or contract with a federal agency and regardless of whether the motorists consenting to giving a human sample are compensated or not.