A Vietnam War veteran has been arrested and charged with murder in Philadelphia following the fatal shooting of a man authorities say was an undocumented immigrant and part of an international conman gang. George Barr, 75, is accused of shooting and killing 20-year-old Salis Hanrahan last Wednesday.

Police responded to Barr's home in the Roxborough neighborhood where Hanrahan, a resident of Essex, England, was found with a gunshot wound to the chest. Neighbors reported hearing shouting before Hanrahan stumbled out of the house and collapsed. He later died at a hospital.

Federal officials have identified Hanrahan as a member of the "Traveling Conman Fraud Group," a group of British and Irish nationals accused of defrauding clients through shoddy construction work and overcharging for incomplete projects. The Department of Homeland Security confirmed Hanrahan was in the United States illegally after having his visa denied due to his alleged affiliation with the group, which the FBI has designated as a transnational criminal organization.

The extent of Hanrahan's involvement with the alleged fraud ring is not yet clear. Construction workers had been on Barr's property for several days prior to the incident.

Barr, a retired firefighter, was arrested two days after the shooting and charged with murder, possession of an instrument of crime, and recklessly endangering another person. A neighbor described Barr as polite and kind, noting he was involved in the unofficial neighborhood watch. The incident remains under investigation.