Can you use video footage to tell a person's weight?

Police in Philly released a video of an attempted child abduction in an attempt to gather tips from the public. My Dad, watching the evening news with me, was furious that they didn’t give out more facts to help people find the perpetrator. In particular, he decided that the police (since they knew the height/weight of the children in the video) should be able to calculate the weight of the man.

I can see a number of problems with my Dad’s logic, but I thought I’d put the Dopers to work on telling me exactly how wrong he is.

There might be a way to estimate the perp’s weight but to what end? You have a picture of the perp, what more can be needed? Is someone going to say, “Yeah it sure looks like Bob but he only weighs 260, not 275. Must not be him?”

Too bad the cctv wasn’t a little better, they would have a good license plate shot.

He was also upset that they couldn’t use automotive know-how to determine the exact make and model of car. When I reminded him that you can’t just say “enhance” and expect a zoomed-in, high-resolution image of the car, he wasn’t amused. He seems to think that every white sedan has a specific body shape that an automotive expert would be able to identify. I think he watched to much Vinny.