The incident that led to the Rob Kardashian vs. Paparazzo arrest didn't appear to be a "joke" when it was happening ... because the photog told police, "He tried to kill me" ... and it's all caught on tape.
TMZ broke the story ... Rob was handcuffed and arrested early Sunday morning after chasing after a paparazzo and cornering him in a bong shop. Rob insisted he was just "joking" with the pap.
But new footage has surfaced ... which shows Rob was in a very heated argument with a super attractive female moments before the incident. It appears Rob gave chase to the pap AFTER he realized the argument was being recorded.
The pap ran to the nearby smoke shop to hide out ... but Rob spotted him and followed him inside. Cops saw the chase and darted inside the shop ... bursting into the store as Rob was closing in on the photog.
Once the pap sees the cops ... he yells out, "He's attacking me ... he chased me ... he tried to kill me." During the video, Rob never lays a hand on the pap.
The officers grabbed Rob and asked him why he was in the shop ... to which the reality star replied, "I'm shopping."
Kardashian was placed in handcuffs and warned, "Don't resist."
According to the police report, obtained by TMZ, Rob confirmed to cops that he gave chase because he "did not like the paparazzi filming him."
Eventually, cops determined there was no altercation, and let both men go.