“Of those three departments, only the Little Rock Police Department contacted federal agents for a child pornography investigation, prosecutors said in an August 9 court filing.”
It sounds like the police departments were downloading child pornography and then not initiating an investigation. That does not sound appropriate to say the least.
No, they probably have a unit for crimes against minors and cybercrimes. Whatever they saw probably had nothing to do with their jurisdiction and may already have been in Federal possession.
It’s possible that somebody was following up on another name that had some connection to Dugar. It’s also possible that somebody was just curious to see if there was any foundation to the charges, and accessed it for that reason...which is illegal. But they weren’t doing it for fun.