Police Tuesday were still investigating an incident where a 4-year-old boy was killed in traffic in Tampa Sunday night. But recent evidence has changed detectives’ minds about what might have happened, the Tampa Tribune reports.

At first, a witness said that Marterrance Albury had fallen out of a moving SUV at Florida and 109th avenues. The vehicle, a dark green or black 2000-2004 Ford Expedition, fled the scene. A witness said the child hit his head and was run over by the vehicle’s back tires. He died from his injuries at a local hospital.

Marterrance’s 17-year-old brother was babysitting the child when Marterrance disappeared from the family’s nearby apartment. According to a news release from Tampa police, the boys’ mother, Johntea L. Williams, went out with friends Sunday night and left the preschooler in the care of his older brother.

Just after the incident Sunday night, the 17-year-old approached the scene and told an officer that he couldn’t find his little brother.

The boys’ mother was told about the incident when she returned home around 4 a.m. She “became hysterical and wanted to take her own life,” according to the release. She was taken to a hospital for her own protection.

A recently discovered surveillance video shows what detectives believe is the silhouette of Marterrance walking along the road shortly before the 911 call was placed around 10 p.m. Sunday.

While detectives were originally investigating the possibility of Marterrance being pushed out of the moving SUV, now they believe he may have left the apartment and wandered into the road, where he was struck, the Tribune reports.

Evidence from the video and an autopsy report align with the new theory, the Tribune reports. But on Tuesday morning, police said they are no closer to finding the driver of the vehicle.

“Based on the injuries to the child, the physical evidence at the scene, the witness statements and different camera angles, it appears the child was the victim of a hit-and-run or a traffic crash,” police spokeswoman Laura McElroy told the Tribune. “It is possible that the driver did not realize the child was hit.”

Anyone with information is asked to call Crime Stoppers at 1-800-873-8477 or the Tampa Police Department at 813-231-6130.