A driver has been found not guilty by reason of insanity of causing the death by careless driving of a baby boy in a pram.
Five-month-old Louis Thorold was hit on the pavement of the A10 near Cambridge, on 22 January 2021. His mother Rachael was seriously injured.
Lawyers for Shelagh Robertson, 75, said she had undiagnosed dementia at the time of the crash in Waterbeach.
Jurors at Cambridge Crown Court found her condition had affected her driving.
Mrs Robertson, of Stables Yard in Waterbeach, was driving home from the supermarket when she turned into the path of an oncoming van, forcing it on to the pavement where it hit the mum and baby, the trial heard.
Louis was pronounced dead on arrival at hospital.
Mrs Thorold spent 10 days in a coma and 118 days in hospital, with her husband Chris describing her survival as "miraculous".
Mrs Robertson denied causing the infants death by careless driving.
During the trial, James Leonard, defending, said Mrs Robertson was "ill-equipped to negotiate" the junction due to her dementia, while prosecutor David Matthew said that while there was "strong evidence" she had dementia, there was the question of "where on the slope of dementia Shelagh Robertson was in January 2021".
Adam Zeman, professor of cognitive behavioural neurology at the University of Exeter, compiled a report on Mrs Robertson for the defence.
He told the court she had "dementia caused most probably by Alzheimers disease in a slightly atypical presentation".
He said this would have put Mrs Robertson at "high risk of becoming confused at that junction and one possible outcome of the confusion would be to look the wrong way".
The judge, Mark Bishop, told jurors that if they were satisfied on the balance of probabilities that the defendant had dementia at the time, and either did not know what she was doing or did not know that what she was doing was wrong, they could return a special verdict of not guilty by reason of insanity.
As jurors returned their majority verdict, Louiss parents, Chris and Rachael Thorold, who sat in the public gallery, looked down at the floor, with Mr Thorold shaking his head.
Speaking after the trial, Det Sgt Mark Dollard, from the road policing unit for Cambridgeshire, said: "This was an extremely tragic and sad incident and our deepest condolences go out to Louiss family.
"Regardless of the verdict nothing will ever bring Louis back and his family will have to live with that for the rest of their lives.
"It is however, a stark reminder of how important it is for anyone who gets behind the wheel of a vehicle to be competent and capable of driving safely.
"I would urge anyone who is concerned about a family member or friend and their ability to drive to speak up, discuss your concerns with your loved one or alternatively speak to your GP who can submit their concerns to the DVLA."
The judge adjourned the case for a further hearing on 19 August.