BAKERSFIELD, Calif. (KGET) -- Detectives first asked about the bruising to the young girl's back. Then they questioned him about injuries to the 2-year-old's lower jaw and upper lip. Gregory MacDonald, the child's stepfather, said they occurred while he tried to help her. He told police he struck her back "really hard" to get her to spit out a large piece of ham, and, in a separate incident, he pried her mouth open when she bit his finger. Detectives then asked about other injuries found after the girl's death on Oct. 10, those visible on her feet, forehead, buttocks and the back of her ears. MacDonald denied knowing how they occurred. They pressed him. Not all those injuries were an accident, were they? Noting he and his girlfriend had recently moved in with several other people, they asked if he'd lost his temper under the stress of adjusting to the new living situation. Chandy McCarthy, file image "MacDonald remained silent momentarily before saying, 'Probably had a bad day, probably was hard for me that day," according to newly available police reports. Both MacDonald and the child's mother, Chandy McCarthy, are charged with second-degree murder, assault on a child under 8 resulting in death and child cruelty. They're being held without bail and are due back in court in January. Police say MacDonald -- who was previously arrested in Nevada on suspicion of harming the child -- abused the girl at intervals for months. McCarthy knew about it, police say, didn't get help and "likely contributed." On Oct. 10, police were called to a home in the 300 block of Vernal Place in central Bakersfield to a report of a child in medical distress. The girl was taken to Memorial Hospital, where she was pronounced dead. Bruising was visible over much of her body, reports say. McCarthy denied knowing about the abuse, saying she noticed the bruises about a week ago but MacDonald explained them as accidents, like the child falling off the bed, according to the reports. She said sometimes she heard the twins crying and saying "ouchie." That morning, McCarthy told police, the child had been vomiting and napping often. She said she called 911 after noticing her lips turned blue and her eyes rolled back. MacDonald told investigators he tried to help the girl by forcing her to vomit and giving her CPR, and the injuries likely occurred then. A detective asked if he agreed the injuries appeared excessive. "Yeah, I mean, like I said, like I said, (I'm) new, I never really went to CPR class, never did anything like that, so on whatever I was doing, I was trying, learning as I was going," he said according to the reports. MacDonald denied shaking the child, but McCarthy said after the girl became lethargic she saw him drag her from the bed to the floor, blow in her mouth and shake her, the reports say. Regarding their contacts with Child Protective Services and Reno police in Nevada, the couple said they believed McCarthy's mother -- who previously lived with them -- lied in police reports about MacDonald hurting the girls. McCarthy said MacDonald was arrested in Reno for "a couple of knots and things on the girl's head." "Everything was dropped," she added. Police say neither McCarthy nor MacDonald showed any emotion when told the child had died. "So me trying to blow her stomach up didn't help at all," MacDonald said.