How can my son effectively screen tenants?

[worriemama]

He brought a house in London. He now wants a tenant. How can he find people who:

1. Aren't criminals/dangerous people
2. Won't treat him badly and steal from him etc.
3. Would pay their rent on time
4. Don't tend to smoke/take drugs/host loud parties

Can he make his tenants go though a basic dbs check? Shall he look at their CVs and ask for character references?
Shall he only room with teachers, childcare workers and the like?
Is there an agency he can use?

Use an agency

For a house mate? Who you have to share living space with every day?

No way. It's important to meet any applicants to have an idea of whether you're going to get on. And the applicants need to meet the present occupant/s for the same reason.

This is what spareroom and openrent are for.

I'm sure many do think like that. But I didn't have any trouble finding a lodger to live with me and two young children in what was definitely an unequal relationship (my house, my rules) I think the setup attracted quieter people who wanted a reasonably clean and civilised house with less unpredictability than some house shares. In a house share you either rent as a group (and risk responsibility for each other's share of the rent) or your landlord chooses your housemates. So both these models have their downsides too.