Police said Mr Cashford was assaulted following a disturbance involving a small group of people in the Warden Bay Road area, close to Jetty Road, at 19:00 BST on Sunday.
He sustained"multiple injuries" to his body, a police spokesperson added.
A car was seized by officers as part of the investigation.
Kevin McKenna, MP for Sittingbourne and Sheppey, previously said he was"deeply saddened and shocked by the tragic incident".
Kent Police said it was continuing to appeal for any witnesses to come forward.
Anyone who has information or who has CCTV or dashcam footage is urged to contact the force.