He decided on the spot that if Paul was to return all the money he wouldn't press charges so he called his parents and asked them to find out where he was.

press 在这里是动词，意思是"施加压力"或"坚持要求"，引申为"正式提出"的意思。 charges 是名词 charge 的复数形式，charge 在这里指"正式指控、控告"。 press charges 是一个固定短语，意思是"正式提出指控"或"起诉"，指向司法机关正式举报犯罪行为并要求追究法律责任。