Justin Bieber -- D.A. Doesn't Want CELEBRITY JUSTICE

The L.A. County District Attorney wants to make sure Justin Bieber is treated like Joe Schmoe when they charge him with egging his neighbor's house ... and that's why the case hasn't been filed.

Law enforcement sources involved in the case tell TMZ ... prosecutors are still evaluating 2 factors in deciding whether to charge Bieber with a misdemeanor or a felony. First, the D.A. is digging deep into the exact amount of damage the yoking cost the homeowner.

As we first reported ... the homeowner submitted estimates to the L.A. County Sheriff's Dept. putting the total tab at around $20K.

The D.A. is also looking at similar cases they and other law enforcement agencies have prosecuted, to determine if a misdemeanor or a felony is most appropriate. They don't want this to look like "celebrity justice." The complicating factor -- they've already charged Lil Za with FELONY vandalism for breaking a $400 jail phone.

Our sources say the amount of damage isn't the only factor. The egregiousness of the act is also a big factor.

Notice we are not couching this post by saying Bieber might not be charged. That's because we're told he will be charged ... the only issue is whether it's a misdemeanor or a felony. If you're betting, go with the former.