JMO but:
highly unlikely: police officer uses their job as a reason to stop a complete stranger and do something untoward to them.
far more likely: a person (who happens to be a police officer) is seeing/having some sort of relationship with a woman who already has a boyfriend. Woman arranges to go to his flat to end it/finish an argument/discuss things. Something goes horribly wrong (‘crime of passion’) - officer flees to eg his mum’s house (note he was ‘arrested in Kent’, not ‘from Kent’).
MOO but think this sounds far more feasible than rogue officer using his role to commit crimes against women. Not impossible - but less likely IMO.
Also think the accident scenario is a possibility - esp if eg there was drink driving involved - but for reasons people have already said, harder to cover up or to happen without anyone noticing.