From LA County comes the LA County Homeless Outreach Portal, LA-HOP:
Do you see someone experiencing homelessness who needs help? Notice a homeless neighbor who seems to be struggling with their physical and/or mental health? Then you can help them by filling out an outreach request and alert LAHSA and LAHOP as to any specific concerns you may have regarding the person’s well-being.
For more information and to get started: https://www.lahsa.org/portal/apps/la-hop/request