WIXOM, Mich. – 
Shell casings found in Perry, Mich., may represent the first big break in the case of mysterious shootings at vehicles on roadways from mid-Michigan to southeast Michigan near Interstate 96.
Read: Reports of roadway shootings in Michigan now up to 22
Police have a sketch of the suspect described as a young man with closely cropped hair who was driving a black sedan, possibly a Chevrolet/Oldsmobile Alero or Toyota Camry.
As of Monday evening, 22 shootings have been reported. Ten have been reported in Wixom, 10 more in Ingham County, Oakland County, Livingston County, and two in Perry and Shiawassee County. No one has been injured in the shootings.
Police are sitting at highway off ramps to deter the shooter and provide help if another shooting occurs. School recesses have been canceled for Wixom's elementary and middle schools.
Read more: Mysterious shots fired at vehicles in Wixom
It has been unnerving for many who frequent the areas where shootings have been reported.
"I have family who live in Wixom and have a couple of nieces and nephews who just got driver's licenses, and it's scary because Wixom is a good place to live and it's highly regarded," said Renee Maggi.
Wixom's police chief says they will get their man.
"We don't tolerate this stuff in our community or in our town, and all of the law enforcement reps in the communities affected think likewise," said Chief Clarence Goodlein.
The communities involved are on edge, hoping everyone's luck holds out and no one gets injured.
Police say they are searching for a man using a semi-automatic handgun, not a rifle. They are working to prove that all 22 reported incidents are definitely the same shooter. They have the full services of the Michigan State Police Crime Lab along with their polygraph operator. Federal investigators also are involved. Police are throwing everything they can at this case to make sure no one gets injured.
Wixom schools to remain under 'shelter in place' on Tuesday
Walled Lake Community Schools, which covers schools in Wixom, sent a letter home to parents on Monday saying schools will be under a "shelter-in-place" policy for one more day -- Tuesday.
"After consultation with law enforcement authorities, we have been advised and cleared that the shelter-in-place can be lifted. However, to ensure safety, security and process, Superintendent Gutman has asked that we maintain the shelter-in-place for one more day, through Tuesday," the letter reads.
Michigan State Police troopers are sitting at highway off ramps to deter the shooter and provide help if another shooting occurs.
-- Perry, Mich. is a city in Shiawassee County about 20 miles from Lansing, Mich.