Authorities hope a $12,000 reward is enough to uncover "information leading to the arrest and conviction of the individual(s) responsible for these crimes," MLive reports Wednesday afternoon.
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is offering a $10,000 reward and CrimeStoppers is offering $2,000.
Earlier, authorities said fragments of seven bullets found at shooting scenes in Wixom and Livingston County came from the same gun.
The Oakland County Sheriff's Office Forensic Laboratory analyzed the bullet fragments from the seven sites, Undersheriff Michael McCabe said, according to Mike Martindale in The Detroit News.
"We can't say with certainty what caliber weapon they came from at this point," McCabe told reporters. "But seven of these incidents are from the same weapon."
Evidence from other shooting incidents is being reviewed by the Michigan State Police.
From Oct. 16-18, police said 22 shootings were reported in Oakland, Livingston, Ingham and Shiawassee counties, most aimed at vehicles along the Interstate 96 corridor. No injuries have been reported.
