MINNEAPOLIS — A Minnesota football coach accused of taking pornographic videos of his children is offering a simple explanation: The images are nothing more than innocent family antics, unfairly misinterpreted by authorities as having the darkest possible motive.

That defense, first presented by Todd Hoffner’s attorney last week and reiterated by his wife on Monday, will face tremendous scrutiny by investigators in the days ahead and a likely challenge by prosecutors before a jury, experts said.

“Where you draw the line is through investigation,” said Meg Garvin, the executive director of the National Crime Victim Law Institute in Portland, Ore. “Because sometimes the pictures you first see in a child pornography case might be very similar to benign family photos, and it takes more investigation to determine that, as well as experts talking to the children. And that’s sometimes how we’ll find out what’s happening.”

What they’ll discover is nothing illegal, said Melodee Hoffner, whose husband is the football coach at Minnesota State University in Mankato. In the family’s first statement since her husband’s arrest last week, Hoffner called the charges against her husband “ridiculous and baseless.”

“My family does what every family does — we take videos and pictures of our kids in all their craziness,” Melodee Hoffner said Monday.

Hoffner, 46, of Eagle Lake, was arrested last week and charged with two felonies: possession of child pornography and using minors in a sexual performance or pornographic work. Capt. Rich Murry of the Blue Earth County Sheriff’s Office said officers seized computers, discs and electronic equipment when they searched the coach’s home following his arrest, and that material is being searched for any relevant evidence.

Experts who reviewed authorities’ descriptions of Hoffner’s videos said to determine the innocent from the nefarious, detectives will try to uncover whether the videos were kept secret or if other adult family members knew of them. While debating whether to file charges, they said, officials often consider whether there are multiple pictures or videos and whether the children are acting naturally for their age.

Marsh Halberg, a prominent defense attorney in the Minneapolis-St. Paul area, said such investigations rarely yield close calls. He cited a case in which his client was investigated for taking a picture of her naked toddler on a beach. It was seen by day care workers, who went to authorities.

Officials searched his client’s home and conducted interviews to determine the context of the photo, Halberg said. They decided not to charge his client.

“Usually, when I have a child porn case, this hasn’t been a gray line,” he said.

In Minnesota, the legal definition of child pornography includes performances depicting actual or simulated sexual conduct, and the definition of sexual conduct includes masturbation or lewd exhibitions of the genitals. That’s typical of state and federal laws on child pornography, which generally define videos or photos as such if they include images that have the intent of evoking a sexual response, said Parry Aftab, a New Jersey attorney and online child safety advocate.

A naked child in the bathtub is not pornography by itself, she said, but a nude girl with her legs spread or a boy touching his genitals meets that definition.

At a court hearing after Hoffner’s arrest, his attorney, Jim Fleming, said the videos show nothing graphic, abusive or exploitive and defended them as “private family moments.” Hoffner’s wife said Monday the couple’s three children love to dance, play and act silly, and to be photographed and recorded.

“I assure you our children have not been exploited or abused — they are healthy physically, mentally and emotionally; and have normal relationships with friends, family and teachers,” said Hoffner, who works as a guidance counselor at Mankato East High School.

Cordelia Anderson, a Minneapolis-based consultant on the prevention of child sexual abuse and exploitation, said one of the things investigators likely will look at is whether Hoffner was directing the children. The description of the videos offered by authorities state a man’s voice can be heard, but does not include what is being said. The described actions don’t sound like those of children between the ages of 5- and 9-years-old who were in front of their parents, she said.

“Children can be smiling. Children can be laughing. The adult can be very skilled at setting this up as a game at these ages,” Anderson said.

Fleming rejected such assessments of the videos: “I don’t know how they can say it when they haven’t seen (them),” he said.

Hoffner has been placed on leave at Minnesota State, where he was entering his fifth year as football coach. Authorities said they uncovered the videos after Hoffner brought his university-issued phone to the school’s information technology department earlier this month because it wasn’t working properly. An employee came across the videos and reported them to his superiors.

“There was certainly something in what they saw that concerned them. It’s good to see they were willing to report it,” Anderson said.