Future just dropped a killer new track -- the hook's all about O.J. Simpson and double murders ... and includes a line threatening an unnamed dude who's trying to "f*** my baby mama."
The track from DJ Esco's mixtape is called "Juice" -- and includes the lines: "Murder trial, O.J. Simpson. White on white, O.J. Simpson. Double murder, O.J. Simpson."
But then he spits this line ... "Tryin' to f*** my baby mama, dog what's up with you? You gon' make me get a heat, I'm pullin' up on you."
Of course, with Future's very public beef with baby mama Ciara -- people are already asking the question ... is this about Russell Wilson???
We reached out to Future's camp -- so far, no comment.