We broke the story ... Lee -- a top UCLA recruit in Jim Mora's famed 2013 class -- was arrested last year after law enforcement says he was involved in an altercation at a weed dispensary that turned violent.

According to court docs, obtained by TMZ Sports, officials say Lee and at least 2 other men entered Kings Palace Marijuana Dispensary in Jurupa Valley, Calif. on June 30, 2016 ... when someone from the group shot a store employee.

Officials say a security guard in the store returned fire ... and that's when they say Lee and the other suspects bolted out of the place.

After an ensuing 3-year-long investigation into the incident ... law enforcement claimed the whole thing was a robbery gone wrong, and say a key witness told them Lee's role in it all "was to grab drugs and money and run."

Lee was eventually hit with 3 felonies by prosecutors ... including attempted murder, attempted robbery, and accessory for allegedly aiding the others to flee.

But, a rep for the Riverside County District Attorney’s Office tells TMZ Sports Lee agreed to a deal this month ... pleading guilty to the accessory count.

In exchange, the prosecutors agreed to drop the other 2 charges.

We're told Lee was sentenced to 80 days in jail ... but was given credit for time served and won't have to spend another day behind bars.

Lee was also hit with 36 months of formal probation ... but prosecutors say if he keeps his nose clean for two years, he'll have the opportunity to have the felony conviction reduced to a misdemeanor.

As part of his probation terms, Lee, among other things, cannot possess a firearm or leave the state without first getting permission.