RedactedNarrative: While on duty I was dispatched at 2150 to a non-injury boat accident at a residence with a dock on the Spokane River. Radio updates reported the suspect vessel was traveling down river toward the Post Falls boat launch. During my transit, I observed 3 large cabin cruisers not meeting the description of the suspect vessel traveling up river. In an attempt to prevent the vessel from exiting the river at the boat launch, I passed the scene and proceeded to the boat launch without overtaking another vessel. During my transit back to the scene, I stopped and inspected 2 open bow white boats. They had no visible hull damage and were longer than the suspect vessels. 
  
  When I arrived on scene at 2256 I contacted the Reporting Party and another person, who had both witnessed the accident. 
  
  Witness2 provided the following information: They were seated in their living room when they heard a loud noise coming from the river. Looking out the window they observed a 24' white ski boat sitting approximately 25 yards down river from their dock. 
   
  They exited the house and walked to the dock noticing there was damage to the upriver side with missing deck boards. The cloud covered half moon did not allow for identification of the vessel's registration numbers. The boat was stationary and Witness2 hailed the operator to see if it needed assistance. After a few minutes the operator responded that he was not injured, restarted the engine and traveled upriver to the day shape 20 marker. The vessel remained in the area for about 5 minutes then traveled across to the north side of the river and appeared to try to dock in a slip. Witness2 illuminated the vessel with a flash light and the vessel then proceeded down river. Witness2 lost sight of the vessel after it turned off it's navigation lights. He believes it pulled into a vacant slip on the south side of the river. 
  
  Due to lack of adequate lighting, Witness2 and I made plans for me to return to photograph the damage on the following morning. 
  
  I returned to the scene 1148 on 07/22/2015 photographing the damage. The photos were downloaded to a CD and entered as evidence. Point of impact was 3' from the end of the dock on the up river side. There was an 18" long 1/2" gouge on a 6" X 6" timber near the point of impact. Several deck boards were damaged or missing. The exit point 12' from impact was marked with prop cuts. Based on the distance from impact to exit point I estimated the vessel speed in excess of 20 MPH . 
  
  During my transit back to the boat house I inspected vessels in slips along the north shoreline for hull damage, finding none.
   