Cops certainly knew who they were arresting when they threw the cuffs on Rajon Rondo earlier this year … as police body cam footage, obtained by TMZ Sports, shows officers discussed his NBA career just after pulling him over.

The stop, as we previously reported, happened back on Jan. 28 in Jackson County, Indiana … after authorities alleged Rondo’s black Tesla didn’t have a license plate properly secured to its rear.

The video shows that after initially speaking with Rondo and obtaining his information … cops went back to their squad car — and chatted for a few moments about the ex-Celtics guard’s time on the hardwood.

Later during the stop, one of the cops on the scene actually brought up Rondo’s NBA career to his face — asking him straight up, “You played in the NBA, didn’t you, buddy?”

When Rondo told him yes and for how long, the officer exclaimed, “Wow!”

Unfortunately for Rondo, his fame didn’t help him much during his run-in with the police … as he was still arrested by the cops after they said they discovered a small amount of weed, drug paraphernalia and a gun in his ride.

The 38-year-old four-time All-Star, who last played in the NBA during the 2021-22 season, was hit with three charges over the encounter … although back in September, he reached a plea deal with prosecutors to close out the case.