The officer was on her way home from a late shift when she saw the victim with her head in her hands near Dover Road, Deal in the early hours of Sunday 7 November 2021.
The off-duty officer took the victim to the home of a family member and an investigation was launched into how she had come by her injuries.
Lee Dardani, who was known to the victim, was quickly identified as a suspect and he was arrested later the same morning.
Enquiries by the East Kent Vulnerability Investigation Team suggested the assault had taken place in or around Priory Station Approach Road, Dover.
A witness was traced who saw the victim in that area being followed by Dardani shortly before 1am, saying he had hit her.
Further investigation also showed that Dardani’s car had been in both areas at the relevant times.
The 49-year-old, of Downs Road, Walmer, was charged with assault occasioning actual bodily harm, which he later admitted at Canterbury Crown Court.
On Wednesday 23 February 2022, Dardani was jailed for a year for the assault and made the subject of a two-year restraining order, which will prevent him from contacting the victim following his release.
PC Jess Meadway, Kent Police’s investigating officer, said: ‘Police officers do not stop caring for victims when they go off duty and the officer who saw this woman while driving home quickly spotted the signs that something was not right.
‘Protecting women and girls from violence is a priority for Kent Police and I am pleased that our investigation has seen this violent man sent to prison and a court order imposed which will protect his victim.
‘I urge anyone who is being mistreated or abused by someone they know to report it to us as soon as possible, so we can take action to protect them from harm and bring wrongdoers to justice.’