TMZ Sports has obtained photos of the bloody scene at Marco Pappa's apartment -- after the MLS player was stabbed ... showing a bloody knife and a blood trail from the kitchen to the bathroom.
As we previously reported, cops say ex-Miss Washington Stormy Keffeler called 911 on Dec. 17th to report an accident at her boyfriend's Seattle apartment -- but when cops arrived both she and Marco told cops they had no idea what happened.
Marco was stabbed in the torso and needed surgery -- he denied Keffeler was his attacker.
But check out the pics ... cops say they found a bloody knife in the kitchen and a blood trail that led to the bathroom. They say they also found stab marks on the wall.
Cops sent the knife to the crime lab to be checked for fingerprints -- but no prints were recovered.
For the record, officials tell TMZ Sports Stormy has NOT been charged with a crime, however the case is still under review.
11:45 AM PT -- TMZ Sports has also obtained a copy of the 911 call in which Stormy initially tells the operator, "I had an accident at my boyfriend’s apartment."
When pressed, Stormy later says she has no idea how Marco was stabbed.
At one point, an emergency responder can be heard saying, "This sounds suspicious to me."
11:54 AM PT -- Another interesting twist regarding Marco's brother, Jose -- who had previously told a major Guatemalan newspaper that he was visiting Marco in December and never heard about the stabbing.
The twist ... is that Marco gave a statement to detectives at the hospital following the stabbing and Jose WAS THERE ... even identifying himself by name.
So, the question ... why would Jose lie to the media?