Officer Goes Flying Headfirst Trying to Catch Courthouse Escapee

A man convicted of drug possession made a break for it in court, and despite an insane, all-out effort by a deputy to catch him ... the guy escaped and is still on the loose.

The video's wild -- Nicholas Garrison had just been sentenced Tuesday in Highland County, Ohio after being found guilty of aggravated possession of meth, when he decided to make a run for it.

Garrison broke free from the bailiff who was trying to slap the cuffs on him. A couple officers gave chase, and you gotta see how one went diving over a railing in an attempt to nab Garrison. He came up empty though, and in the most painful way.

As Garrison continued down the stairs, the poor deputy also continued down -- but he was sliding on his back. Court officials say he suffered a concussion and 4 broken ribs.

Garrison is still at large and his attorney, Kathryn Hapner, tells us ... he was hoping to just get probation, but the judge sentenced him to 6 months PLUS an additional 530 days for violating parole on a previous burglary conviction. All told that would be nearly 2 years in prison.