Who is the murderer?

Jimstantham Police Station.
In the conference room, Jackson sat in front of the computer.
A surveillance video is being played on the computer screen.
The time was 10:30 last night, the location was the bank of the Xiangjiang River, the picture was a little dim, but generally clear.
From the picture, we can see that Adaline is facing the Xiangjiang River, maintaining a posture of making a phone call.
Taking out his cell phone, Jackson glanced at the call records, checked the time,...