A man who was found mentally incompetent over a crash that killed two women — including decorated South Australian Police Detective Chief Superintendent Joanne Shanahan — is facing a civil lawsuit.

Harrison Kitt is being sued for damages by one of the first responders to the Anzac Day 2020 crash at Urrbrae, in Adelaide’s south.

Jacqueline Ross has lodged a District Court claim seeking $100,000, alleging she continues to suffer PTSD, anxiety, depression and a panic disorder as a result of what she describes as Kitt’s negligence that day.

She claims the trauma has limited her ability to carry out domestic tasks, participate in social and recreational activities, and has caused a loss of income and earning capacity.

Kitt is yet to file a defence.

Harrison Kitt is being sued by a first responder to a deadly Adelaide crashHarrison Kitt is being sued by a first responder to a deadly Adelaide crash Credit: 7NEWS Harrison Kitt, 20, ran a red light at speed before hitting two other cars, killing two women in their 50sHarrison Kitt, 20, ran a red light at speed before hitting two other cars, killing two women in their 50s Credit: 7NEWS

The civil action comes almost six years after Kitt walked free from court, having been found not guilty of causing death by dangerous driving due to mental incompetence.

Kitt was behind the wheel of the car that crashed into two other vehicles, the crash killed Shanahan, 55, and St Peters mother-of-two Tania McNeill, 53,

Kitt sped through the busy Fullarton and Cross Rd intersection at Urrbrae at 160 km/h, running a red light while on the wrong side of the road.

His car became airborne before slamming into Shanahan’s Holden and McNeill’s BMW.

Prosecutors conceded Kitt was in the grip of a psychotic episode at the time.

The court heard he had a diagnosis of bipolar disorder and was experiencing his first severe manic episode, marked by grandiose and bizarre delusions.

He was placed under strict mental‑health and parole‑board supervision, ordered to live with his parents, and banned from driving for 10 years.

Ross’ civil claim will return to court in June.

Iconic Adelaide CBD buildings were lit up in blue in memoriam of a decorated police officer killed in a smash at UrrbraeIconic Adelaide CBD buildings were lit up in blue in memoriam of a decorated police officer killed in a smash at Urrbrae Credit: 7NEWS