The Mankato college football coach charged with child pornography for three brief cellphone videos of his three dancing, naked children won't appear in court until Oct. 31.

But now that searches of Todd Hoffner's home and car, as well as equipment and records at several previous employers, have yielded no similar images, it's time for Blue Earth County Attorney Ross Arneson's office to break the public silence it has maintained on the case since Hoffner's high-profile arrest in August.

Reassurance is needed that moving forward meets the office's own charging policy, which includes these stated criteria:

• "The prosecutor should file only those charges which he or she believes can reasonably be substantiated by admissible evidence at trial."

• "The prosecutor should properly exercise his or her discretion to present only those charges which he or she considers to be consistent with the best interests of justice."

With Hoffner's reputation shredded, there should be no uncertainty at this point whether the images meet legal guidelines for child pornography. While no one outside of law enforcement and the family has seen the videos, the descriptions that are available in court documents continue to generate considerable unease across the state about whether the footage reflects bad parenting or criminal behavior.

Arneson needs to explain now why his office believes the legal line has been crossed, not let the question linger until the end of this month. Instead, his office has ducked questions. Last week, he declined an interview with an editorial writer, saying his office "doesn't try our cases in the newspaper."

Hoffner is the head football coach at Minnesota State University, Mankato. According to the Aug. 22 criminal complaint, a technician doing repairs on his university-issued cellphone discovered two home videos of Hoffner's children -- ages, 9, 8 and 5 -- cavorting in the nude. The videos last about a minute and 10 seconds. The footage shows two of the kids bending over and spreading their buttocks. An 8-year-old boy is also shown touching his penis.

A third video lasting about two minutes shows Hoffner's daughter being awakened at night to "go potty." Footage focuses on the girl's buttocks, which are covered in flowered underwear.

While Hoffner's wife and his attorney have defended the videos as kids being kids, the children's ages and behavior make the images disturbing. The cute photos that many parents take of their young children splashing around in the bathtub, for example, generally end with toddlerhood.

The bending over and the boy's touching his penis are even more discomfiting. But it's unclear given the available information whether the videos depict "actual or simulated sexual conduct," as child pornography is defined in Minnesota statute. Whether that grave charge is justified may well hinge on contextual information not made available, such as whether the camera zooms in on intimate parts of the kids' anatomy, what Hoffner said to them, or what he intended to do with the footage.

Last week, the coach's defense attorney, Jim Fleming, said that there are no zoom-ins on the kids. He also said reports that Hoffner was audibly "directing" his kids are untrue and that there's no evidence that Hoffner had even viewed the videos since the images were recorded this summer.

Hoffner unquestionably showed poor judgment by using a university-issued cellphone to shoot and store these images. University officials did the right thing by reporting what they found. If there's a question about children's well-being, it should be checked out.

But authorities who act on this type of information should be comfortable explaining their decisionmaking. Arneson needs to detail why he's certain that the images meet the legal criteria for child pornography. He also needs to head off concerns that his case is weakened by the failure to find similar images elsewhere. Explaining why he chose not to convene a grand jury to weigh charges would also be relevant.

Providing this information is not trying the case in the newspaper. It's simply being accountable for your actions to the public that gives prosecutors enormous powers over individual lives.

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