Richardson police said they are awaiting test results before making an arrest in a hit-and-run that hospitalized an 11-year-old boy.
Devin Byrd was riding a go-kart when he was struck and dragged Thursday evening on Twilight Trail near his grandmother's home.
Police confirmed that they sent several pieces of evidence to a lab for analysis and plan to hold off on making an arrest until the results are available.
On Friday, investigators impounded the sport utility vehicle believed to have been involved in the crash to gather evidence.
Police also questioned the owner of the SUV, but police have filed no charges against her.
Devin was playing on a go-kart on a sidewalk near his grandmother's home when a black or dark-colored SUV swerved off the road.
Police presume the driver was turning onto Floyd Road.
Devin was dragged several feet, and the driver sped off.
Witnesses said the woman had a white dog in the vehicle with her when the incident happened.
Byrd remains in critical condition at Children's Medical Center, said Karen Morris, his grandmother.
She said her grandson was "mutilated" by the accident. He sustained massive head trauma, a broken leg and cuts and bruises all over his body from being dragged.
Police are continuing their investigation and following more leads in the case.