Polisi mengatakan, motif utama serangan itu adalah pembalasan atas insiden yang terjadi beberapa pekan sebelumnya ketika scooter Murphy rusak setelah bentrokan dengan sekelompok pemuda Asia.
Police said the main motivation for the attack was revenge for an incident that had occurred a few weeks earlier when Murphy's scooter had been damaged after a confrontation with a group of Asian youths.