SAN ANTONIO -- A woman said Thursday that she witnessed a pattern of bad parenting prior to the death of a 3-month-old boy.

In an interview with KSAT 12 News, Stephanie Bernal said that she saw John Sharkey yell and handle his son, Keegan, a little too roughly.

Sharkey was arrested and charged with capital murder Wednesday in connection with the death of his son.

When asked if Sharkey was a good father, Bernal said "No, he wasn't at all. John would constantly yell at the baby."

Bernal said that she got to know Sharkey and his wife when they and Keegan stayed at a friend's apartment recently.

She said that in additional to the yelling, Sharkey mistreated his son.

"Throwing him into the crib, covering his face with a pillow, constantly shaking him," Bernal said.

Sharkey admitted to investigators Tuesday evening that he caused harm to his son, San Antonio police said.

Authorities were called to the SAMM Ministries on Saturday morning in response to an injured child call, police said. When Keegan was taken to Christus Santa Rosa Hospital, the child was dead on arrival, police said. There were no obvious signs of trauma, police said.

An autopsy performed the next day revealed that the child had suffered multiple skull fractures, police said. One of those skull fractures is attributed to an accidental fall from a baby carrier, said Mary Walker, a spokeswoman with Child Protective Services.

"I just can't believe he did that, think like that," said a man outside the shelter.

The July fall was not the first time the family had been investigated for possible neglect charges, Walker said, but an investigator found no evidence in the first case, which came four days after the child was born in June.

The child's 24-year-old mother, who has not been identified, has not been charged, police said.

Bernal said that Sharkey belongs in prison.

"He needs to have some kind of severe punishment, because that was a baby," she said. "He was only 3 months old. He had no fault in anything that went on in John's life."