The jury at the inquest into the deaths of brothers Eoghan and Ruairi Chada has returned a verdict of unlawful killing for both boys.
Witness statements from 16 people were heard during the course of the inquest.
The boys were murdered by their father Sanjeev Chada outside Castlebar in July 2013. Sanjeev Chada pleaded guilty in October, and is now serving a life sentence.
The coroner's court proceedings today were attended by the boys' mother. Witnesses included those who discovered the bodies and gardaí who attended the scene of the crash.
The cononer's court heard that witnesses prevented Sanjeev Chada from taking his own life. It was only when they noticed the child's seat in the car that they examined the vehicle further and discovered the two boys' bodies lying side-by-side in the boot of the crashed car.