That's why I bust back, it don't phase me
When he drop, take his Glock, and I'm Swayze

from 2Pac (Ft. The Notorious B.I.G.) – Runnin' (From Tha Police) Lyrics on Rap Genius

An officer is shooting at him, but B.I.G. isn’t scared to fight back against the police! He even stole the officer’s gun after he killed him by shooting back and then left the body.
“Swayze” is slang for gone, out, leaving, etc. The term is derived from the title of the film Ghost starring Patrick Swayze, since “ghost” is also slang for making one’s exit

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