The man who allegedly killed Nipsey Hussle went off the rails shortly before the incident, and pistol-whipped a guy over a drug deal gone wrong ... this according to new witness statements submitted to prosecutors.
The L.A. County DA's Office got the account from 2 women who say a male friend told them he was attacked at his apartment by murder suspect Eric Holder ... just an hour before Nipsey's murder.
According to the statements ... Holder lived in the same building as the guy and they sometimes hung out and smoked pot. The guy's story goes like this -- Holder showed up at his place around 2 PM on March 31, and he was pissed. He accused the neighbor of selling him weed that was laced with some other drug.
They went into the hallway to talk, and according to the statements ... Holder was "breathing very heavily and appeared very excited and very agitated." When Holder got more hostile, the neighbor tried to return to his apartment but was allegedly pistol-whipped in the back of the head.
According to the statements ... the neighbor was knocked down, but still conscious and claims he saw the gun on the floor. He describes it as a "big silver gun" and "semi-automatic."
The neighbor got up and safely retreated to his apartment, but says Holder was "shaking and looked very nervous" before leaving.
The women -- repped by attorney Harley D. Breite -- claim their friend admits to selling Holder $10 worth of pot, but it was straight from a dispensary and not laced, to his knowledge.
The neighbor told the women he learned a few days later that Holder was the suspect in Nipsey's murder case, but he was afraid to report his encounter because he knows Holder's a gang member. Plus, he DID sell him marijuana.
We broke the story ... Hussle was shot around 3 PM in L.A. on March 31 and pronounced dead at 3:55 PM at a downtown hospital. Video of the incident shows a man -- believed to be Holder -- shooting Nipsey outside his Marathon clothing store.
Holder was arrested 2 days later and eventually charged with murder. It's unclear if Holder intends to raise the allegedly laced weed as part of his defense.