A 75-year-old Vietnam veteran has been arrested and charged with murder in the fatal shooting of a 20-year-old British national who was working on his Philadelphia home.

Authorities identified the deceased as Silas Hanrahan, an illegal immigrant from England. He was reportedly part of a construction crew hired to work on the home of George Barr, 75. According to police, a commotion was heard from inside the residence shortly after 2 p.m. last Wednesday, followed by a gunshot.

Hanrahan emerged from the house and collapsed on the sidewalk with a gunshot wound to the chest. He was pronounced dead shortly after. Hanrahan was from Essex, England, and is described as a member of the Irish traveler community.

Department of Homeland Security officials confirmed that Hanrahan entered the U.S. illegally and had been denied an Electronic System for Travel Authorization (ESTA). He was affiliated with what officials described as "The Traveling Conman Fraud Group," a group designated by the FBI as an organized crime gang. The group is reportedly comprised of British and Irish scammers who overcharge for building work and then fail to complete it.

Hanrahan is part of the traveler community and originally hails from Essex, in the east of England

Investigators have not released further details regarding Hanrahan's alleged links to organized crime or whether he was suspected of targeting Barr. Hanrahan leaves behind a wife and a young daughter.

Police said last week that contractors were out back putting siding on the home shortly after 2pm when a shot was fired from inside the home

Barr, identified as a retired firefighter and Vietnam veteran who reportedly ran an unofficial neighborhood watch, was arrested and charged with murder, possession of an instrument of crime, and recklessly endangering another person. Court filings indicate he was arraigned last Friday and is scheduled for another court appearance later this month. His plea has not yet been entered.

Hanrahan was working with a construction crew who said they heard a commotion, Hanrahan then walked out of the home and collapsed on the sidewalk

Neighbors described Barr as friendly and expressed shock at the incident, noting the area is typically quiet.

According to court filings seen by the Daily Mail, Barr was arraigned last Friday and is next due back in court later this month