Looks as if they really were a couple of people who should have been on a secure ward rather than out and about. One of them isn't even in a fit state to be sentenced at the moment.
I think there are real concerns about the level of support patients with severe mental illness like schizophrenia receive. I thought the whole point of having depot injections was to ensure that people got the medication they needed if they could not be trusted to take them orally
They mention in the article that one of the convicted pair deteriorated when he didn't take his medicines (there's a surprise!) and that he stopped taking his medication some time before this plot was hatched.
What I don't understand is why people are just left to stop taking their medicines and deteriorate to a stage when something bad happens like suicide, attacking complete strangers or hatching bizarre plots like this one. I realise that there are laws protecting individual freedoms, but when that results in harm, it seems as if we may have got the application of the laws wrong.