NEW DETAILS EMERGE IN ALDON SMITH CASE: According to Santa Clara PD: Aldon Smith...

NEW DETAILS EMERGE IN ALDON SMITH CASE: According to Santa Clara PD: Aldon Smith crashed into parked car at his condo complex & left his SUV; police then responded & he failed a sobriety test. The 49ers released Smith earlier this morning.

ALSO: TMZ Sports is reporting Aldon Smith got into a scrap with QB Colin Kaepernick that may have been the trigger for Smith going off the rails and ending up in jail.

Multiple Niner locker room sources tell TMZ Sports ... Aldon and Kaep had an altercation on the field during Thursday's practice, and "players had to pull them apart." There's been a lot of Internet buzz recently that Smith's ex-girlfriend is now dating Kaepernick.

Indeed Smith and Hot 97 host Nessa broke up in recent months, and even though she and Kaep have not been photographed together ... rumors they're together have persisted. TMZ sources say it wasn't clear if Smith and Kaep exchanged any words before the fight broke out ... or if Nessa's name ever came up.