I have wondered if the statement from Kam's dad is a bit of the same as the one from Bryer's dad in that neither one of them had real reason to think the other kid was a bad influence but once the 2 teens are suspected of murder, the natural inclination is to assume the one who isn't yours is the bad element and the instigator.
Bryer's dad was more blatant about it but still danced around the issue with "not trying to offend Kam's family" but "my son didn't have a vehicle, couldn't drive, and didn't have access to real guns," with the implication being that since this murder rampage involved a road trip and guns, that must be on Kam.
I don't remember the sequence of who released what first, but I wonder if between the lines, Kam's dad is basically saying not trying to offend Bryer's family but my son is kind, caring, and considerate, so a murder rampage that is the exact opposite of treating people with kindness, care, and consideration, that must be on Bryer.
Again, not saying either one actually had concerns about their son's friends before this happened, but I think their instinct is to take what they think they know about their child and assume that actions suggesting the opposite are the fault of the other suspect.
Just MOO