The 8th day of testimony in the Diddy trial is in the books and prosecutors are still trying to gain headway on the racketeering charges against the mogul … and one of their witnesses even thinks he helped Diddy’s defense.

Wednesday opened with Homeland Security Investigations agent Gerard Gannon detailing more about a raid on Diddy’s home on Star Island … a search that turned up guns, ammo, drugs, lube, baby oil, sex toys and lingerie.

Interesting stuff … and maybe the guns help prosecutors prove a RICO case against Diddy … ’cause some of the serial numbers on the magazines were scratched off.

Next up on the witness stand was psychologist Dawn Hughes … and she testified about reasons victims stay in abusive relationships.

The defense characterized Dawn as a professional witness — she also testified in the Amber Heard–Johnny Depp trial and will do so in trials involving Harvey Weinstein and R. Kelly — but folks in the court room tell us jurors seemed to be interested in what she had to say.

The third and final witness was George Kaplan … a former executive assistant for Diddy who testified about setting hotel rooms up for freak offs … complete with lube, baby oil and candles. He also said Diddy gave him money and a number to call to secure drugs, and Kaplan would execute the transaction and give the drugs to Diddy.

Prosecutors again seem to be trying to prove a criminal enterprise being run by Diddy — the RICO charge — and Kaplan will be back on the stand Thursday when court resumes.

Kid Cudi is also expected to testify … and he could help prosecutors gain major ground if he has evidence Diddy blew up his car … but if Kid Cudi only has second hand knowledge Diddy was behind the incident, the defense will pounce and use hearsay to block his testimony.

No one really knows what Kid Cudi will have to say … so stay tuned.

Outside the courtroom, we talked with exotic dancer “The Punisher” on “TMZ Live” … and he told us he doesn’t know why prosecutors called him as a witness and believes his testimony may have helped Diddy, because he didn’t see any criminal aspects to his sexual encounters with Diddy and Cassie.