Justin Bieber -- Smoking Gun in Egging Case -- Surveillance Video

The L.A. County District Attorney has surveillance video that should make it pretty easy to prosecute Justin Bieber for allegedly egging his neighbor's house ... TMZ has learned.

Law enforcement sources tell us ... The L.A. County Sheriff's Department's recommendation to file felony vandalism charges focuses on 2 pieces of critical evidence:

-- Surveillance video seized during the raid at Bieber's house. Our sources say ... the video shows Bieber in the vicinity of the area where the egging occurred at the time of the attack. You don't actually see him throwing eggs, but he's there. Sources connected with Bieber told TMZ earlier the video shows nothing, but that's NOT true. The Sheriff's Dept. has given the video to the D.A.

-- A video obtained by TMZ in which you hear what sure sounds like Justin Bieber verbally going at it with the neighbor in the middle of the egging. At one point you ever hear Bieber scream, "F*** you! I got another one for you actually." The video is too dark to actually see him.

In addition there are 2 eyewitnesses ... the neighbor ... who openly has beef with Bieber -- and his 13-year-old daughter. The girl made a 911 call which our sources say matches the time Bieber was seen on the surveillance video.

The 2 videos make it almost impossible for Bieber to deny he was throwing the eggs -- it would be shocking if the D.A. doesn't file criminal charges.

The open question -- will the D.A. file the case as a FELONY or a misdemeanor? The neighbor has submitted repair estimates totaling around $20,000. If a vandal destroyed an expensive car the D.A. would probably view it as a felony. The issue is whether the D.A. will appreciate that eggs can cause that much damage on an expensive home.

The D.A's decision should come down this week.