NFL Owner Art Modell -- Cops Find Grave Urinator ... Kick Case to State Attorney

Cops have finally identified the Cleveland Browns fan who peed on the grave of late Baltimore Ravens owner Art Modell ... and now the case is the hands of the State Attorney ... TMZ Sports has learned.

The footage has been all over the Internet -- showing some pudgy dude in a Lyle Alzado jersey calling Modell a "piece of s**t" who tried to kill the Browns ... before taking a leak on his gravestone.

Now, the Baltimore County Police Department tells us ... they have positively ID'd the suspect and "made contact" with him during the investigation.

We're told cops interviewed the suspect -- and took a report -- which has now been sent to the State Attorney's office which will decide whether or not to prosecute the urinator.

Unlike the perp, officials are trying to make to make sure details from the report don't get leaked.