There's an easy answer to that - he didn't think he would get caught. It was everything about money!!
Why would you have read about a similar case where the 'perpetrator' got away with it? If they got away with it no one would know! But there are quite a few instances of murder for gain.
He must be very backward if he didn't think he'd be caught considering he must have known he'd be the only family member left. Perhaps not a psychopath------------just a raving lunatic.
He wasn't in debt ( which is usually a marker ) He had a regular well-paid job ( which is another marker if you haven't ) and he had no money worries ( yet another reason why people kill----desperation )
I thought psychopaths were clever enough NOT to get caught. Though in my estimation,Jeremy wasn't clever,intelligent,but not clever. A clever man wouldn't have told police how to get in through a window,nor would he have disposed of a silencer by putting it back in the cupboard----dirty.A clever man wouldn't have rang the police-period !! Because by doing so,he implicated himself straight away. A clever man would have kept his moth shut at all times and not given police any information until a lawyer was present.Clever ? I don't think so.
Sheila was the one with money worries,health worries,marriage worries,debts,no job,loneliness,unloved.etc etc.constant battles with her mother.