This is Florida. Pam Bondi oversaw Baker Act revisions.
Yes. A family member can say magic words like “erratic behavior”, “he’s living with a mental illness” and describe some actions to police and they may determine he is a clear and present danger to himself or others. They remove all guns from the house and they take him away.
They act fast here in Florida which is GOOD. But once the guns are removed, and someone is Baker Act’d for 72 hours, the chances of being allowed to ever buy a gun again in Florida are close to zero. And good luck getting a court appearance to fight it.