Inside Peter Brown's altered cultivation room, there was a surveillance system, which he had purchased back on Earth. Now, the entire Spirit Field was being monitored by this system.
Of course, the surveillance equipment wasn't like the ones on Earth. For Peter Brown, a Master Refiner, modifying it was easy. On the surface, it looked just like a set of plants and trees. Moreover, the system didn't employ divine sense for monitoring, thus even cultivators wouldn't sense anything.
Ever since Peter improved the power supply with electricity, the surveillance system could function here.
Each location had a signal reception point set up. Peter could monitor the entire Spirit Field while sitting in his house.
After killing that old man, Peter was observing the crime scene. What he needed to determine was whether the culprit was sent by Zariah Nelson or not.
Sure enough, after observing for a half day, a man appeared there.