I am reading 'The Man Who Fell To Earth" and it's about this supposedly very smart martian who makes very basic mistakes that led to his capture. There is a quote, something to the effect, 'it's amazing the number of things you just don't think about'. Which I think is true and why people got caught. Truth is, he had a lot on his mind and that can make you very clumsy.
I doubt he was arrogant. I think he was on the run and didn’t have any place to put away the evidence. Probably homeless this whole time. And had to go to get food at some point.
Probably hadn't really thought through the specifics of tossing evidence.
Bodies of water are popular for disposing of things, because it's a huge PITA to find things there. Imagine how hard it might be in a large local pond, and then multiply that in complexity for a rather big river. Or an inland sea like the Great Lakes. Don't even multiply for those; it's a stupidly big irrelevant number.
It's been several days, he had plenty of time to wipe stuff down and dump it. I don't think this is arrogance necessarily, perhaps isolation and paranoia.
> I doubt he was arrogant. I think he was on the run and didn’t have any place to put away the evidence. Probably homeless this whole time. And had to go to get food at some point.
He totally did. Find a trash can, and put it in (though maybe disassemble the gun first, and dispose of it in pieces in multiple locations).
He "became quiet and started to shake" when asked if he had recently been to New York, according to the criminal complaint filed in Pennsylvania.
Being smart can lead to arrogance, which leads to stumbles. like carrying evidence, dining in public, etc.