Kellen Winslow Jr. just appeared in court -- where a judge ordered him to be held without bail because of "clear and convincing" evidence he poses a threat to the public.
Prosecutors also revealed two of Winslow's alleged rape victims -- a 54-year-old and a 59-year-old -- are both transients ... according to NBC's Artie Ortega.
The ex-NFL star faces a slew of criminal charges, including kidnapping and rape ... and family and friends are inside the San Diego courtroom to support him.
One of Kellen's supporters is his father, Kellen Winslow Sr.