Police investigation remains open. The photo of one of the minors included a fly; that is the logo of Clothoff, the application that is presumably being used to create the images, which promotes its services with the slogan: “Undress anybody with our free service!”
Not necessarily, solutions can implemented. For example, footage from private security cameras can be sent to trusted establishment (trusted by the court at least) in real time which can be timestamped and stored (maybe not necessarily even stored there, encryption with timestamp may be enough). If source private camera and the network is secure, footage is also secure.
All they’d need to send to trusted servers is some basic metadata and hashes of segments of video. That’s enough to verify that the video hasn’t been tampered with after it was filmed as long as you trust the hashing function.
I don’t think that will matter very much considering how many real time video modifications we can do already today. Not to mention synthesizing video before the time it is supposed to take place.
Network security is a pretty big ask though - just look at how many unsecured cameras are around now. And once an attacker is in anything generated on that network becomes suspect - how do you know the security camera feed wasn’t intercepted, manipulated, or replaced altogether?