"Why did he do it? I don't know. I don't know if we'll ever know," said Wriggelsworth, who called the attacks "domestic terrorism." He said he wants federal prosecutors to take the case.
Before the arrest, clues appeared to be few: slugs and bullet fragments embedded in cars, metal casings on roadways, a simple black-and-white sketch of the shooter - a man believed to be in his late 20s or early 30s - and vague descriptions of the dark car he drove.
The crime scene where the shootings took place is 100 miles long and slices through suburbia, shopping malls and farm pastures. Shootings have occurred during the day, at night, on weekdays and at weekends. Police say the shooter drives along roadways and fires at vehicles traveling in the opposite direction. Only one person was wounded.
Initial reports of shootings stirred panic. Wixom schools restricted recess and other activities that would take students outdoors. Drivers avoided main thoroughfares where they might be exposed and stuck to side streets.
But police have been working hard to maintain calm. In Wixom - where 10 shootings have been reported - police had special Halloween patrols to protect trick-or-treaters. From Oakland County, northwest of Detroit, to Shiawassee County, northeast of Lansing, authorities stopped cars resembling the shooter's vehicle. A $102,000 reward was offered.
"I've always felt safe here. But this has been very shocking," said Karen Adams, 51, who lives one street away from the suspect.
When state troopers flooded the area Monday night, she figured it was related to the investigation. Adams stopped her daily walks while the shootings were unsolved.
"There's lots of angry people out there," she said.