The CPD secured the house about 10 hours before they had the search warrant, they told BC to leave. At that point all evidence was in the hands of the CPD, in their possession. We don't know when they entered the house specifically, or if they followed protocol. We don't know if even two LEOs did go in togther if they stayed together once inside, and it appears there are many rooms in the house. Once they obtained the SW it was another 12+ hours before the laptop was powered down. In total the laptop was powered up for 27 hours. The reasoning given was that unplugging it would have corrupted data. They have not been able to adequately explain what made the 27th hour the magic hour.
We do know that the FBI agent was unaware of this lapse of protocol. We also know that CPD has not released the chain of evidence records for the laptop. Finally, we know that they erased NC's Blackberry, and that protocol was not followed with that at all, they didn't even have a SW when they erased it and requested the SW after they had erased it.
They didn't even need to turn the laptop off. All they had to do was unplug the cable modem or router. That would have isolated it unless the laptop was set to automatically connect to a different network.