What worked best in my experience is having a roundtable discussion between all the interviewers about their experience, and any concerns or objections they have. i.e. soft veto.
The hiring manager had the ultimate say, though. But he/she had to acknowledge, address, and own any objection and take personal responsibility for it if the candidate was hired.
When you have a good team who is earnestly focused on preserving a good team, it works really well. Red flag objections were pretty much never ignored, and were effectively vetoes. Minor objections or slight concerns about experience or aptitude, if they were overridden, prompted hiring managers to take extra time and care to help ensure the new hire's success.
There are a lot of things you can take from it, but one overarching opinion is that "housing first" gets in the way of helping those who are down on their luck and find themselves hopefully-temporarily without a home (as opposed to those who cannot or will not work to change their situation).
It makes the case you need multiple approaches to deal with the vastly different homeless situations.
The hiring manager had the ultimate say, though. But he/she had to acknowledge, address, and own any objection and take personal responsibility for it if the candidate was hired.
When you have a good team who is earnestly focused on preserving a good team, it works really well. Red flag objections were pretty much never ignored, and were effectively vetoes. Minor objections or slight concerns about experience or aptitude, if they were overridden, prompted hiring managers to take extra time and care to help ensure the new hire's success.