Clues appear to be few: slugs and bullet fragments embedded in cars, metal casings on roadways, a simple black and white sketch of the shooter and vague descriptions of the car he drove.
Investigators searching for a man responsible for shooting at two dozen vehicles along freeway corridors in four counties are up against anonymity and a 100-mile-long crime scene that slices through suburbia, shopping malls and Michigan farm pastures.
Fear has prompted some to drive along side streets rather than heavily used thoroughfares. In Wixom — where 10 of the 24 shootings have been reported — police planned special Halloween patrols to protect trick-or-treaters. From Oakland County, northwest of Detroit, to Shiawassee County, northeast of Lansing, authorities are stopping cars resembling the shooter's.
Even reports of something slamming against a windshield or two drivers involved in a spat initially have been considered as developments in a case that now involves more than 100 local officers, state troopers, sheriff's deputies and federal agents.
"I hope they catch him. Me and the other drivers are a little worried," said Frank Bommarito who chugs along part of the Interstate 96 corridor daily while hauling produce. "They haven't shot at any truck drivers yet, but there's always that chance. I don't know if it's a guy in a car or some guy sitting out in the weeds or bushes, but it makes us pretty nervous every day."
The shootings started Oct. 16 in Wixom, a blue-collar community about 25 miles northwest of Detroit. The shooter hasn't kept still, hitting vehicles along I-96 and connecting roads in Livingston, Ingham and Shiawassee counties. Shootings have occurred during the day, at night, on weekdays and on weekends.
Only three of the shootings have been on the busy freeway.
"It's almost like we're chasing a ghost," said Gene Wriggelsworth, Ingham County sheriff. "It's not easy or we'd have him. We don't have a license plate or a name to work on. And the description we have is from a person who was shot at at night."
Eight shootings have been in Ingham.
Officials are not tipping their hand to the various strategies at work, but roads are saturated around the clock with marked and undercover vehicles. Police put together a sketch from one witness.
So far, only one person has been wounded.
Eventually, the man responsible will likely make a mistake and get caught, said Dr. Steven Pitt, an Arizona-based forensic psychiatrist. Pitt was part of a police task force that searched for the so-called Baseline Killer in Phoenix for a series of attacks that began in 2005. Mark Goudeau was found guilty of nine murders in the case last year.
"As a serial offender achieves serial success they become increasingly brazen," Pitt told The Associated Press. "When you become increasingly brazen you become less careful and more sloppy. You make mistakes and when you make mistakes that ultimately leads to your apprehension."
Police say the I-96 corridor shooter drives along roadways and fires at vehicles traveling in the opposite direction.
As tips flood in — more than 2,200 as of Wednesday afternoon — police also are working to maintain a sense of calm.
Early on in the case, schools in Wixom restricted recess and other activities that would take students outdoors, according to Wixom Public Safety Director Clarence Goodlein.
"We are giving special attention to our schools. We have some schools along the route where shootings took place," Goodlein said. "For Halloween, we are going to do special patrols in each of our subdivisions so kids can have a normal Halloween."
At least seven of the shootings in Wixom happened on Wixom Road. Gas station owner Eddie Osman said police are reviewing surveillance video from the 32 cameras in and around his shop on the road near I-96.
Customers are "pretty scared. They know that this is some kind of crazy, psycho guy," Osman said. "My business has went down — big time. Everybody in this neighborhood has lost customers."
"Some people tell me that they are breaking the law by speeding on Wixom Road because they are scared of slowing down," he said.
Though apprehensive, Bommarito gassed up his truck Wednesday at Osman's station before heading back onto I-96 from Wixom Road.
"I would probably find a different route, but because I'm a (truck) driver that's my shortest way," he said. "I really have no alternative routes. I'm sticking on 96, unfortunately."
In the end, it could be a driver like Bommarito who helps break the case.
A reward was upped Monday from $12,000 to $102,000. About 1,300 tips have come in since the reward was increased.
"It's going to be one person picking up the phone and giving us that piece of information," said Michael Bouchard, Oakland County sheriff. "The payoff is when we can put an end to this and everyone is committed to doing that — hopefully before anyone else is hurt or killed."