A man will be sentenced next year, after he plead guilty to dangerous driving causing the death of a 66-year-old man near Ardrahan in 2016.
A Garda was seriously injured in the same collision.
Adrian Nestor, with an address at Keamsella, Kilcolgan, pleaded guilty to charges arising from the collision in which Liam McDonnell was fatally injured on 1 February last year.
Mr McDonnell had been reported missing from a nearby nursing home the previous night.
Nestor pleaded guilty to a second charge of causing serious bodily harm to Garda Sharon Casserly.
She and a colleague had been involved in a search for Mr McDonnell, when a car driven by the accused struck the three of them on the N18.
Mr McDonnell was pronounced dead at the scene while both gardaí were taken to hospital.
At Galway Circuit Criminal Court today, Nestor also pleaded guilty to driving while drunk.
The court heard he had a blood alcohol reading of 272 milligrams of alcohol per 100 millilitres of blood at the time of the collision.
Sentencing was adjourned until January, pending the preparation of probation and psychiatric reports.
Nestor has been remanded on continuing bail until then.