All things considered, this name appeared as a clue, but it seems like he had nothing to do with each incident.
This is the third clue.
Zheng Yuandong said, "In the Laojun Mountain incident, the fire burned down more than a dozen inns, destroying the accommodation registration forms as well. Due to the lack of network connections, we couldn't retrieve the check-in records."
Xiao Ying said, "Right, the Road Team even went personally to sift through the ruins, but found nothing."
Zheng Yuandong said, "You all overlooked one thing, nowadays everyone likes to book hotels in advance through apps. I found Jiang Xue's reservation on Meituan."
"Jiang Xue didn't have a private car, so I went on to find the bus station's passenger records for those days, and nowadays, riding a regular bus requires an ID card to purchase tickets, so I discovered that Qing Chen was also on that bus."
So, Qing Chen was on Laojun Mountain that night as well.
This is the fourth clue.