KHOU in Houston said Peterson hit a different 4-year-old son last year, leaving a scar on the boy's forehead. That can be used as evidence in the current investigation, the report said.
TMZ reported, citing sources, that the case "went nowhere" because he did not strike the child, but the child accidentally hit his head on a carseat while Peterson was punishing him.
According to KHOU, Peterson sent a text message to the boy's mother saying he hit his head on a carseat. When questioned further, Peterson said in a text that he hit the boy, according to KHOU's report. Here are the texts, from KHOU:
Mother: "What happened to his head?"
Peterson: "Hit his head on the Carseat."
Mother: "How does that happen, he got a whoopin in the car."
Peterson: "Yep."
Mother: "Why?"
Peterson: "I felt so bad. But he did it his self."
Further text messages showed that Peterson was disciplining the boy for cussing at a sibling, KHOU said.
The boy involved in the incident last year and the boy who was allegedly disciplined by Peterson with a switch this past May (the incident for which Peterson was indicted) are from different mothers, KHOU said.
KHOU reported there is a photo of the boy with two bandages over his eye, and then another photo allegedly taken weeks later "reveal a scar over his right eye."
No charges have been brought in the case in which the boy suffered the scar, and it's unclear if the Vikings knew about it. KHOU said, citing sources, that a report was filed with Child Protective Services, but results of the investigation are unknown.
The Vikings deactivated Peterson for Sunday's game against the Patriots, then reinstated him on Monday. He is expected to play in Week 3. The team repeatedly talked about allowing the legal process unfold. Peterson's trial isn't expected to take place until 2015.