OKLAHOMA CITY, Oklahoma - Minnesota Vikings player and former OU standout Adrian Peterson is at the center of a second abuse investigation. The case involves another one of Peterson's sons, who's also four.

Text messages allegedly show Peterson telling the boy's mother, he whipped him for mouthing off to his sister.

9/15/2014 Related Story: REPORTS: Peterson Accused Of Abusing A Second Child

A picture from an incident last June, shows a head wound to a boy, said to be Peterson's son.

The mother filed a report with Child Protective Services but no charges were ever filed.

Peterson is charged with child abuse after he used a switch to discipline another of his sons.

9/12/2014 Related Story: Former OU Star Peterson Indicted For Child Injury In Texas

Oklahomans are at odds over whether that spanking was actually abuse. The law here specially allows parents to spank their kids, but it leaves a lot of room for interpretation.

Oklahoma parents reacted to the injuries left behind on Adrian Peterson's 4-year-old son after a whooping.

“Back in my day as a spanking, that was considered a light spanking,” said Oklahoma resident, Carlos Spencer.

Oklahoma resident, Dani Tull said, “In my opinion, what he did was too much, but to someone else, it may not be.”

They are split on Peterson's case, as well as the broader issue of corporal punishment and when that form of discipline crosses the line.

“I'm really a bad one for that because I didn't spank my son, he just got time out and grounded,” said Tull.

Spencer said, “That's how I got to where I am today. It molded me. Spanking does mold. The Bible says spare the rod, spoil the child, so at some point, you have got to do the proper discipline.”

Oklahoma law allows any parent to use "ordinary force as a means of discipline including, but not limited to, spanking, switching, or paddling."

What it doesn't specify are injuries. According to DHS policy for investigating abuse, a minor injury on the legs, shoulders, arms or buttocks of a child older than ten years of age is generally not considered physical abuse.

Our expert, Dr. Phil, said Peterson went too far.

“When it gets to the point that there are physical remnants of that spanking, there are welps, the skin has been broken, there is bruising, then clearly it has crossed the line,” he said.

DHS also looks at cultural differences and upbringing when it considers what is child abuse versus reasonable parental discipline.