Roseville police said a 26-year-old man who was stopped on suspicion of shoplifting at Home Depot store stabbed a loss prevention worker with a dirty syringe.
The incident happened Monday evening at the store on 13 Mile Road near Little Mack Avenue.
Police said the suspect, later identified as Joshua Silva, became violent when two workers stopped him and "pulled a concealed syringe from his jacket and using the syringe as a weapon began to swing it about in a slashing motion."
One of the workers was stabbed several times with the "contaminated needle," police said.
A customer, who had a concealed pistol license, was in the store saw what was happening.
Police said the customer pulled his weapon on Silva and ordered him to drop the syringe.
Silva initially stopped struggling, but began running when he heard police sirens. He was tracked down and arrested by responding officers.
Police said the loss prevention worker was treated at a hospital and has been released.
The syringe will be tested by the Michigan State Police Crime Lab for any signs of communicable disease.
Roseville police said they will also be requesting a search warrant to have Silva tested for any infections diseases.
Silva was arraigned Tuesday on several charges: assault with intent to do great bodily harm and retail fraud.