MURFREESBORO (AP) - The American Civil Liberties Union of Tennessee has joined a lawsuit against the Department of Children's Services and the Rutherford County Juvenile Detention Center to end the use of solitary confinement for children.

The Tennessean reports (http://tnne.ws/1N5Rewm) that Monday, a federal judge ordered the release of a 15-year-old with developmental disabilities who had been placed in isolation on April 20.

The boy had been arrested for aggravated robbery, and on March 18 a Rutherford County juvenile judge ordered a mental health evaluation for the teen. However Mark Downton, an attorney for the boy and his mother, says the evaluation didn't take place until after he was released from confinement.

Attorneys for the family are seeking to end the practice of solitary confinement of children. The ACLU of Tennessee announced Thursday that they are joining the lawsuit.