Saginaw police are seeking the drivers of two black sedans as possible witnesses in the slaying of 6-year-old Alanna Gallagher.
Gallagher's body was found in a residential street about a mile away from her home on July 1.
Late Friday afternoon, police released surveillance images of the two vehicles in hopes of identifying the drivers or owners.
Police said investigators have recreated Gallagher's last day through interviews but believe other people may have witnessed something that could be pertinent to the case.
The release of the photos came after someone set fire to a family car and a small memorial for Gallagher at her family's Saginaw home early Friday morning.
Her mother, Laura Gallagher, said the incident was "very frightening." She said she and her family are still struggling with her daughter's death.
Anyone with information on the two vehicles is asked to call 682-888-3682.
The FBI is offering a reward of up to $10,000 for information leading to the identification, arrest and conviction of the person or people responsible for Gallagher's death.