Kansas City, Mo. ? When Kansas City police and paramedics showed up at the scene of a fatal June 20, 2006 car crash, they said they immediately had concerns.

The Honda suffered minimal damage and there were no skid marks to indicate the driver, Charles Mahone, had tried to stop before hitting a small tree.

Mahone told them another vehicle had run his car off the road and he had blacked out. When he came to, he said he crawled through the brush to perform CPR on his 18-month-old stepson, Aaron Marshall, but it was too late.

But the child was cold to the touch, emergency workers said. Then a search of Mahone’s house found blood in several locations and a medical examiner determined Aaron had died of blunt force trauma and asphyxiation.

That was enough evidence for a Jackson County jury, which took less than an hour Friday to find Mahone, 40, guilty of second-degree murder and two counts each of child abuse and child endangerment.

Prosecutors pointed out to jurors in their closing arguments that the bruising on Aaron covered his body, including his ears, legs and genitals and that the child had been suffocated.

Assistant prosecutor Bronwyn Werner said Mahone thought his attempt to hide the child’s death with an accident had worked and even removed his rear view mirror with a screwdriver to trick investigators.

“He’s not a mastermind,” she said. “He’s a wannabe mastermind.”

Defense attorney Molly Hastings challenged the prosecution’s police and medical witnesses, saying their testimony was much harsher than what they listed in their official reports.

“Everybody wants to find someone to hold responsible when a child dies unexpectedly,” Hastings said. For example, she said the blood found in Mahone’s house could have come from other incidents.

She also challenged testimony by a police officer who said Mahone appeared to be “having a ball” after police took him to the hospital. She said he left that out of his official report and, even if true, doesn’t mean her client is guilty.

“He’s not going to react by having a ball while police are watching him” if he were guilty, she said.

Sentencing is scheduled for Nov. 16.