Placidi entered a not guilty plea on Welch's behalf at the arraignment.
Welch is facing trial on charges including first- and second-degree murder in the shooting death of Nadolny on March 23, prosecutors stated in court on Monday. Mead tentatively scheduled Welch's trial for Oct. 12.
The same tentative trial date was given to 20-year-old Erie resident Lexus M. Conner, who was also charged by Millcreek Township police in Nadolny's death. She faces a general count of criminal homicide and other charges.
First-degree murder is a premeditated killing. Second-degree murder is a killing committed during a robbery or other felony. Convictions for both carry a life sentence with no parole.