Double Indemnity

I’m rewatching Double Indemnity and it’s been years since I’ve seen it, it’s almost like watching again for the first time vis a vis certain details. I’ve paused the film right after they pull the train switch. What I’m wondering is, how good were forensics back then? As soon as he pulls the body out of the car, I was thinking, he’ll sling the body over his shoulder and do a fire man’s carry. I couldn’t believe it when he instead started dragging the body. Now I know dna evidence wasn’t developed yet, but that doesn’t mean detectives were entirely in the dark ages back then. Wouldn’t someone have seen the marks left by the body’s heels as it was dragged to the tracks? I’m not positive it was dragged across dirt but it’s a fair assumption. It wasn’t done at a stop with a black top or platform, or along a street, isolated spots where train tracks run are usually through dirt. Let’s say maybe there’s a slightly raised layer or ridge of grit, pebbles etc along side the tracks a foot or two on each side, the way a well maintained track might have. There’d still be a good stretch between the car leading up to the tracks of dirt and dust that would have left furrows for sure.

Did anyone else worry about this? Lol! I know, hey I’m on Reddit, I obviously have some time on my hands lol!😆