A 19-year-old man is going to trial on homicide charges after he was accused of killing his girlfriend's 10-month-old son. 

Dominic Pinnick was arrested after the child died in July, and on Friday morning, he appeared in court for a preliminary hearing. 

During the hearing, a forensic investigator testified that the child's injury couldn't have been caused by falling out of a bed, as Pinnick originally told the police. 

"This was not an intentional death; it was accidental," said defense attorney Phil DiLucente. "I don't know who it was; it was an accident, you heard the judge say it could be reckless, which brings it to involuntary manslaughter." 

Pinnick allegedly told investigators he accidentally bumped Najor Matthews' head against a bedpost while he was trying to soothe the infant, who was crying. 

"Here we have a 19-year-old who is in the care, custody and control of a child, and all he's trying to do is calm the baby down," DiLucente said. 

Despite the claim from the defense attorney, the infant's grandmother said otherwise. 

"The story that was given initially didn't add up to the injury," said Letitia Hawkins. "To me, it's almost a clear-cut case." 

A trial date has not been set. 

Pinnick facing several charges after death of infant

In July, police were called to a home on Kedron Street in Homewood for reports of an infant falling from a bed. 

The child was rushed to UPMC Children's Hospital and was unresponsive while experiencing multiple seizures. He ultimately died at the hospital. 

According to doctors, the injuries were not consistent with a fall, but were consistent with abusive head trauma and violence. The 10-month-old suffered a large skull fracture and numerous retinal hemorrhages. 

Pinnick was charged with criminal attempted homicide and three counts of aggravated assault.