A district crown prosecutor has apologised to the Court of Appeal for an ‘incomprehensible’ decision to charge a man with assault by beating for a ‘terrifying and protracted series of crimes’ against his ex-partner.

The decision to charge Gareth Jex – who strangled his former partner, punched her in the face, threw a butter knife at her and said he was going to ‘disfigure you so that nobody will want you’ – with a summary-only offence carrying a maximum sentence of six months constituted a ‘miscarriage of justice’, Lord Justice Edis said in a ruling today.

His offending ‘was in fact at least one offence of assault occasioning actual bodily harm … seriously aggravated by manual strangulation in the context of sexual jealousy or possessiveness’, the judge said, adding that there were also ‘features of false imprisonment’ and an apparent breach of an existing restraining order.

‘If properly charged, this offence would have justified a very substantial sentence, having regard in particular to the terrible record of the applicant, which includes repeated offences of breaches of a restraining order imposed to protect this victim,’ Edis said.

The decision to charge Jex, from Llwycoed, near Aberdare in south Wales, with assault by beating was ‘quite wrong’, he added. Charging Jex with criminal damage for throwing a vase to the floor added ‘an air of absurdity to the way in which this case was conducted’.

The district crown prosecutor sent a letter of apology to the court, accepting that the charging decision ‘failed to give adequate consideration as to the mechanism of the assault, the use of the multiple weapons and the sustained nature of the attack’.

‘A review of this case and the failings that occurred is also currently underway within CPS Wales,’ the prosecutor added, in order to ‘identify what action can be taken to prevent a repetition of the error’.

However, Edis said that ‘the person to whom an apology is really owed is the victim of the offending … who has not been protected by the system as she should have been’. ‘We trust that this judgment will come to the personal attention of the Director of Public Prosecutions,’ he added.

Jex’s appeal against his sentence – which totalled 56 weeks imprisonment for the assault by beating of his ex-partner and criminal damage, an unrelated count of assault by beating, two offences of fraud by false representation and the activation of a suspended sentence – was dismissed by the court as ‘hopeless’.