How Disablity is represented

Disability has been represented through the way the character acts, as he speaks like a child, and his vocabulary used does seems to be basic. The fact that the detective Frost speaks with him with respective shows that he was aware that he was taking this on board. Most of the evidence pointed against the disabled guy, and the fact that Frost was not harsh in actually getting proper answers from him shows that he was aware that he needed to be gentle with him, which is why he sort of spoke down to him, as if he was a kid.
The actuality that the person in question had his father behind him, in a position that made it look as if he was above him, shows that his Father was watching over him, as if he was a kid, helping with that kid-like image.

Billy, the disabled character's father kneels down at the side of Billy combined with a high angle shot of the Father and Billy, further reinforces the representation of Disability being child-like. This is because high angle shots are typically used to suggest that those being ''looked down'' on are easily intemidated.
The use of a low angle POV is combined with a close up of billy's face invites the audiences to intrepret Billy's facial expressions as being overly suspicious of those in authority.  The actuality that Billy's head is tilt to the side adds to the perception that those who are disabled are easily confused.
Such an insinuation might intrepret the reasoning behind why Billy's father had to explain the reason of the police visit in such simple terms. and why he chose to sit so closely to him, acting as a much needed assistant.

In contrast the combined techniques of reverse editing, low angle framing of shot, and close up of the inspectors facial expression and use of high key lighting lends to the representation that of the abled bodied being more trustworthy and genuine.