Justin Bieber Photog who Died Followed Singer All Day

TMZ has learned the identity of the photog who was killed while shooting Justin Bieber's car -- he's freelance paparazzo Chris Guerra.

Sources tell us -- Guerra, who was in his late 20s -- was following Bieber all day Tuesday. Guerra called someone connected with a paparazzi agency at around 5:30 PM to say he was waiting for Justin, who had pulled into the Four Seasons Hotel in Beverly Hills a short time earlier. Guerra abruptly said the Ferrari was pulling out of the hotel and he had to leave.

Guerra apparently assumed Justin was in the car. As we first reported ... he was not.

Guerra had been working in a Las Vegas casino for several years, when he moved out to L.A. in March to become a photog.

In recent months, he worked the Bieber detail exclusively.