The mother of a Weston teenager jailed for assaulting a serial criminal says 'there's no justice in the world'.

Twenty-four year old Matthew Bowen's been sentenced to four and a half years for attacking repeat offender Dean Mason with an iron bar.

His mum Lynette admits he committed a crime and should be punished, but maintains that the incident was provoked by Mister Mason's dog killing their family cat, something he denies.