Chris Brown Believes the Prosecutor is Out to Get Him

Chris Brown was arrested this week because the woman who prosecuted him in the Rihanna case still has a score to settle ... so claims Chris and his team.

Deputy D.A. Mary Murray was a key player in the decision to have Brown arrested for felony assault with a deadly weapon ... this according to law enforcement sources. Murray has a long and contentious history with Chris. She not only prosecuted Brown in the Rihanna case, she was involved in the various probation violation hearings in which she asked for jail time, and often lost.

Our sources say the day Chris allegedly pulled a gun on a woman at his home, the cops had decided NOT to arrest him, but rather take the case under investigation. In fact, at one point Chris actually came out of the house and was yukking it up with the cops.

We're told it was Murray who pushed a change of plans ... to arrest Chris on the spot.

Brown believes the decision to arrest him was purely punitive ... that the only witness who made the gun claim was a woman with big credibility problems, and he had many witnesses who disputed her story.

Chris has lashed out at Murray in the past. When she got a judge to toss out his community service hours, claiming they were bogus, he left the courtroom and took to Twitter, calling her a racist.

We reached out to the D.A.'s office, but they had no comment.