Seems to me that if ML are going to house specialist residents (and presumably are paid a premium for this), then ML (and Lewisham council) should be held accountable to us, to provide specialist support so they do not present a risk.

ML certainly should hold records on the type of problems the residents have, and have knowledge of the issues any new potential residents may have.
There needs to be qualified staff, who will be experienced in noticing when there are early signs of relapse or new undesirable behaviours and so take pre-emptive measures.

Other councils are not accountable to us, and may 'make a slip' and send people not suitable for this kind of accommodation. Then following an incident, both ML and Lewisham council will claim zero responsibility. This doesn't seem very satisfactory to me, and this is not an arrangement that we should happily agree to be expanded yet further.