The Dane County Sheriff's Office said it is trying to connect up to five random shootings before someone gets injured.
Deputies said shootings on Jan. 1 and Jan. 4 are similar and might be connected to three other incidents on Madison's far east side.
The Jan. 1 shooting was reported at about 9:30 a.m. in the 3300 block of Bailey Road in Sun Prairie Township by homeowners who discovered bullet holes in their home.
On Jan. 4, Bernie Esch, the owner of Electrical Solutions contractors on County Road MN in the Town of Pleasant Springs arrived at work to find several bullet holes in his building.
"It's very concerning -- it could've happened when someone was here," said Esch, who estimated the bullet holes in his large garage door would take two or three hours and $500 to fix.
"It's definitely an eye opener," he said. "It makes absolutely no sense."
Two random shootings happened in Madison on Dec. 29, one hitting a home and another a Chase Bank branch on the east side.
Matt Brown, an employee at Hallmark Drywall and Gypsum Floors in Madison, kept discovering bullet holes at the business until they eventually added up to nearly 20 impact points.
The bullets damaged three work trucks, smashed windows and flattened tires. One flew into the building and blew out the window of a skid loader.
"It's just going to take time," said Brown, adding that the company has insurance. "All these trucks have to be taken in, they all go in separately, and you're looking at a couple weeks for everything to get (fixed)."
Brown said the company's security cameras weren't recording at the time the shooting happened, which Esch's surveillance was pointed in the other direction.
While detectives from the Dane County Sheriff's Office and Madison Police work together to find the perpetrators, business owners should make sure their cameras are working properly, said Elise Schaffer, the sheriff's office spokeswoman.
No one's been injured yet, she said.
"In one case we know the home was occupied when this happened, and it's just really luck that kept somebody from being hurt in this situation," she said.
All the shootings being investigated occurred between midnight and 5 a.m.
Anyone with information is asked to call the Dane County tip line at 608-284-6900 or at danesheriff.com.