Radnor Township Police Superintendent William Colarulo says officers responding to a reckless driving complaint on Friday stopped the former Villanova star.
Colarulo says officers smelled marijuana and recovered a suspicious substance after Cunningham consented to a search. That search also turned up a pellet gun in violation of a local ordinance.
Cunningham was arraigned and released on bail.
The Bobcats released a brief statement Wednesday afternoon. "We are aware of the unfortunate incident involving Dante Cunningham in Pennsylvania," the team said. "We are in the process of gathering more information and will have no further comment until the legal process has run its course."
Portland traded Cunningham to Charlotte in February in the deal that sent Gerald Wallace to the Trail Blazers.
The Bobcats moved Cunningham from power forward to small forward and were impressed with his mid-range jumper. He became a part of the rotation, averaging 9 points and 4 rebounds in 22 games with Charlotte.
Cunningham is scheduled to be a restricted free agent this summer. Before the arrest, Bobcats owner Michael Jordan said they wanted to re-sign him.