"There is no way I would have done that to that little boy."
That was the defiant and definitive claim of Mervyn Bell when asked directly by police whether he had murdered a ten-month boy after taking him from Broome.
Mr Bell, 27, has pleaded not guilty to murdering and sexually assaulting the baby after taking him from his mother's house on March 19, 2013.
The infant had suffered horrific injuries from head to toe, including a broken arm and leg and burns on his feet, legs and body.
The boy also had severe injuries to his genitals and anus.
Mr Bell is accused of intending to kill the baby and inflicting injuries on the child over a 15-hour period before he sped into the Fortescue River Road House with the boy's lifeless body in his arms.
Mr Bell's video record of interview was played to WA's Supreme Court, where he was quizzed by detectives about how the baby boy suffered the catalogue of injuries discovered on his body.
Mr Bell claimed the boy had fallen out of his car as he drove at around 60k/mh.
He claimed he had driven back to find the infant boy lying and crying on the side of the road.
Despite admitting the baby appeared "pretty banged up" Mr Bell said he did not want to take him immediately to hospital, but wanted to get further away from Broome.
He did keep driving, stopping at various fishing holes where he claimed he had washed the infant and cooled him down.
He then said that at one of these pools the baby had ended up face down in the water after slipping from between his legs.
It was then Mr Bell claimed the boy stopped breathing.
When asked directly of he had killed the boy, Bell replied: "F**k no. I did not kill that little boy. I am not a murderer."
CCTV footage captured by police showed Bell buying groceries at 9.50am on the morning of the boy's death, and then buying a six pack of beer around two hours later.
He arrived at the roadhouse at about 1.30pm, when emergency services found the boy dead.
The trial continues.