In Dakota County, the sheriff's office collects DNA samples from those charged with violent crimes, in some cases doing so before the suspect is convicted.

The practice is unconstitutional, says a court challenge issued in late April by the ACLU-MN, which filed a lawsuit against Dakota County Sheriff Tim Leslie.

This is the second time the court has been asked to rule on the case, which could eventually come to trial.

The ACLU-MN sued April 28 on behalf of John Emerson, 68, who was charged with second-degree assault in Dakota County District Court.

Emerson seeks a temporary injunction blocking Leslie from collecting his DNA while his lawsuit is pending, as well as a permanent injunction when his case concludes.

In 2015, Dakota County resumed collecting DNA samples from suspects charged with some violent crimes, including assault — despite the practice having been ruled unconstitutional by the Minnesota Court of Appeals.

The county said it did so because of a U.S. Supreme Court ruling upholding the constitutionality of a Maryland law similar to the one struck down in Minnesota.

"This is an important law which aids in the identification of individuals arrested for serious felonies who are housed within our jails and who are released back into our communities pending resolution of their criminal charges," Leslie said in a statement.

The ACLU-MN said in a statement that it's "suing to prevent Emerson from being forced to undergo an unreasonable DNA search" and the collection of DNA is in "violation of Mr. Emerson's constitutional rights."

"It reveals all kinds of things about you," said John B. Gordon, interim legal director of ACLU-MN. "The idea of collecting DNA from people who have not been convicted of a crime is a step on the road to Big Brother as far as we are concerned."

Dakota County Attorney James Backstrom said the Supreme Court's decision "in my opinion overruled" the state Court of Appeals decision.

"Contrary to the contention of ACLU-MN, we also do not believe this important statute is in violation of Minnesota's constitutional protections," Backstrom said in a statement.

Karen Zamora • 612-673-4647

Twitter: @KarenAnelZamora