Justin Bieber Attempted Robbery Investigation -- D.A. Rejects Case ... No Evidence

Justin Bieber is off the hook for a felony in the alleged phone jacking at a batting cage last month ... because there is ZERO evidence he did anything wrong.

According to the Los Angeles D.A. ... LAPD investigated a San Fernando Valley woman's claim Biebs grabbed her phone out of her purse which led to a tug-of-war between the two ... but cops found nothing to support her allegations.

Cops interviewed 9 witnesses at Sherman Oaks Castle Park ... and none of them saw the singer involved in any sort of altercation.

The D.A. rejected felony prosecution -- and sent the case to the City Attorney who could still charge him with a misdemeanor... but given what cops found, it seems unlikely.

Justin's not totally out of the legal woods, however, 'cause the D.A. is still considering charging him with a felony in the neighbor egging case.