Evans is famous for playing the role of Marvel Comics' Captain America and is putting his real life powers to good use.
The video shared by Evans shows the moment a jogger pushed a woman into the path of a London bus.
The woman was walking across Putney Bridge when the runner barged into her, sending her sprawling onto the ground and into a bus lane.
Her head dangles perilously close to the front of an oncoming bus, which managed to swerve at the last minute and just avoid her, according to the Daily Mail.
Sergeant Mat Knowles, the investigating officer from Putney Safer Neighbourhood Team, said: "The victim was put in extreme danger when she was knocked into the road.
"It was only due to the superb quick reactions of the bus driver that she was not hit by the vehicle.
"We are keen to speak to the jogger in the CCTV about what happened that morning. We would urge him or anyone who recognises him to get in touch with us as soon as possible."
The jogger is described as a white man, aged early to mid-30s, with brown eyes and short brown hair. He was wearing a light grey T-shirt and dark blue shorts.