A 20-year-old Pennsylvania man who authorities say is a “person of interest” in the disappearance of four men last week was sought weeks ago for a felony weapons charge. Cosmo DiNardo was arrested by police in Bensalem on Monday, as local police and the FBI searched his family’s farm for any traces of the missing men. Prosecutors had reportedly asked police to arrest him two weeks ago on a previously dismissed gun charge that stemmed from his possession of a 20-gauge shotgun. DiNardo, who was previously involuntarily admitted to a mental institution, was prohibited from owning a firearm. Bucks County District Attorney Matthew D. Weintraub said Tuesday that DiNardo’s arrest was not tied to the men’s disappearance, though he is considered a “person of interest.” DiNardo was released from police custody late Tuesday after his father bailed him out. Authorities continue to search his family’s farm in Solebury Township for any signs of the missing men, now with the help of cadaver dogs and heavy construction equipment.