A witness at the second murder trial of Michael D. Lane, 28, testified that a 2-year-old boy left in Lane's care last February died of blunt force trauma after he was hit at least seven times on the head.

Sharon I. Schnittker, assistant director of the state medical examiner's office, said that Paul Eugene Watts' death was homicide and that at least one of the boy's head injuries could have been inflicted by someone's foot.Lane, of 270 E. Wilson Ave., is charged with second-degree murder, and began his second trial Tuesday. His first trial on the same charges ended in a mistrial last week after a juror told 3rd District Court Judge Dennis Frederick that he had discussed the case with a member of the defendant's family.

The juror was unaware that the person was a family member, but Frederick said he declared the mistrial to avoid any implication of impropriety.

In previous court hearings, the child's mother, Jennifer Watts, 20, testified that she does not know who injured and killed her son, whom she called "P.J." She and Lane had been living together about two months before the child died.

Watts previously testified that Lane changed the boy's diaper,

dressed him and fed him breakfast the morning of Feb. 10 before she went to church.

She returned home about 1:30 p.m., she said. After checking on the child three times, she decided to wake him at about 5:30. It was then, she testified, that she realized the boy was dead.

On Feb. 11, Watts told detectives the boy had fallen backwards from a sofa and hit his head on a coffee table.

Tuesday, Schnittker said that a head injury resulting from such a fall would not have been lethal.

Schnittker also said that though it was possible a pattern of bruises that showed on the back of the boy's head at his autopsy could have been caused by his shirt collar, it wasn't the most likely cause. The bruises were more likely caused by a person's foot, she said.

"I felt it was a shod foot. I thought it was an athletic shoe," she said.

At Lane's preliminary hearing in March, Salt Lake Police Detective Robin Howell said there was no physical evidence that Lane killed the child. Lane told the detective, however, that he was the only person in the house with the child that day.