Maryland State Police said drugs and alcohol weren't factors in the deadly wrong-way crash on Route 50 in Anne Arundel County.
Toxicology reports came back clean, police said. Now they're looking at possible mechanical problems or human factors for causing the wreck.
Police said that on May 17, 22-year-old Laura Murphy of Salisbury drove the wrong-way for nearly two miles before crashing into 66-year-old Robert Skidmore's car. Murphy had a 14-month-old toddler in her car. Murphy died at the scene.
Rescue crews had to pull Skidmore from the wreckage. He died at Shock Trauma.
The toddler was airlifted to Johns Hopkins Hospital, where he survived.