A 3-week-old girl was found to have a skull fracture and broken leg Saturday in St. Paul, and the baby’s 19-year-old father told police he was in a “blind rage” and “snapped” her leg, according to a criminal complaint filed Monday.

The Ramsey County attorney’s office charged Gerald Monte Hinton Jr. of St. Paul with first-degree assault.

About 2:30 p.m. Saturday , the baby’s mother — who is Hinton’s wife — went to a graduation party. Hinton started calling her about 10 minutes after she arrived to the party.

He left “an angry voicemail claiming that the baby’s leg had been broken after he dropped her and she struck her leg on the counter and … (his wife) needed to come home right away,” according to the complaint.

She returned home to the 500 block of South Fairview Avenue and found an ambulance outside because Hinton had called 911. The baby was taken to the hospital and was found to have underlying brain hemorrhages in addition to the other injuries, the complaint said.

Hinton apologized and repeatedly told his wife that the baby hit her leg on the counter; he told medical staff that he gripped the infant’s “head tightly to break her fall,” the complaint continued. But a child-abuse pediatrician reported that the baby’s head injuries were inconsistent with a short fall.

At first, “Hinton was adamant that his story was the truth,” but after an investigator showed him a photo of the baby and “explained that sleep deprivation associated with a newborn can cause one to become frustrated and overreact,” Hinton allegedly confessed. “You got me. You got me. … I did get frustrated about something, OK,” he said, according to the complaint.

Hinton told the investigator that something his wife “said before she left for the graduation party upset him,” the complaint said. He said “he has anger issues” and the baby “was crying and he became frustrated,” the court document continued.

Hinton also told the investigator that he dropped the baby on her head on the hardwood floor Friday about 1:10 a.m. when he was getting a bottle for her and “he thought he briefly fell asleep while standing,” the complaint said. He said he checked her out and she cried but seemed uninjured. He did not tell his wife “because he did not want to upset her,” the complaint said.

Hinton asked the investigator to tell his wife “that she was right about his frustrations getting the better of him,” that he wanted her “to move on and find a better father because he wasn’t going to be released and was going to serve time,” the complaint said.