RedactedNarrative: on November 18, 2018 I, Cpl.2 responded to the area of Canal Road and Harpers Ferry road at the mouth of Antietam Creek to assist field units with identification of vessel owners of a found overturned 19 foot Tracker.  The vessel had a temporary registration for Maryland and was not in Compass.  I drove to Bowers Marine Sales in Hagerstown to help identify the owners, but the dealer was closed on Sunday, Bowers is the closet boat dealer for Tracker vessels.  Field units were able to find a vehicle and trailer parked at Big Slackwater boat ramp just above Dam 4 on the Potomac River.   At approximately 1620 hours searchers located a female subject about three hundred yards down river from Dam 4 on the Maryland river bank.  Access from the C&O Canal tow path to body was not likely.  Fire and rescue recovered the body and transported her to Taylor's Landing.  I identified the female subject from her driver's license.  
  
  A search for Victim2 continued, but ended about an hour after sunset.  Maryland State Police helicopter advised there was a mass at the base of Dam 4, but were unable to positively identify the mass.  The next of kin for Victim2 was notified and met with myself and Area 7 officers at Big Slackwater boat ramp.  
  
  Subject is a foster brother to Victim2, victim’s biological mother and father are deceased.  Subject informed us that the victims recently purchased the vessel and that Victim2 had recently been released from the hospital for pneumonia.  Subject also advised that Victim2 was at times a risk taker and a dare devil.  I informed Subject that Victim2 was not yet located and asked if he would take the personal belongings of Victim1.  Subject refused to take Victim1's personal belongings, but did not offer any leads to her family members.  
   On November 19, 2018 Victim1 was autopsied at Baltimore Medical Examiner's Office and the search continued for Victim2.  At approximately 0945 hours Victim2 was located by Fire and Rescue approximately fifty yards down river from Dam 4 tangled among some submerged trees.  Victim2 was recovered and transported to Taylor's Landing and FI identified him by his driver's license.  I met with Subject again at Big Slackwater boat ramp and gave him the personal property of Victim2.  Subject also to possession of the vessel, truck, and trailer. 
   On November 20, 2018 I met with half brother to Victim1.  I informed subject2 of the incident and gave him Victim1's personal possessions as well as a contact number for subject1.
   Rangers with the National Park Service gave field officers still photos from a trail camera posted at Big Slackwater boat ramp.  The photos show the Victims launching the boat at 1544 hours on November 16, 2018 and retrieving the vessel at 1644 hours.  The Victims took ownership of the vessel earlier that day and had a fuel receipt in the pickup truck for 37 gallons at 1429 hours at a fuel station on Potomac St. Williamsport, Maryland.  The vessel has a fuel capacity of 21.5 gallons and a 115 horsepower four stroke engine, which efficient fuel economy would last a number of operation hours.  The Victims truck and vessel were photographed launching the vessel at 1345 hours on November 17, 2018 and no other photos of them recovering the vessel.  
  
  A Deputy for Washington County advised that he spoke with the Victims prior to them launching their vessel on the 17th and did not notice anything out of the ordinary with them.  One resident in the area of Dam 4 report seeing a bass style boat about five miles up river from Dam 4 heading down river at approximately 1715 hours.  Another statement made to officers on the night of the 18th was a resident that lived near Dam 4 heard the sound of an outboard heading toward the Dam, but never heard it return and this was after sunset.  Speaking with a friend of Victim2, is that Victim2 was excited to have purchased the boat and was anxious to use the boat.  
  
  Friend believes that Victim2 was new to a vessel or the power of this size.  Speaking with the dealer at Bowers, they indicated that Victim2 was well aware of the vessel he was purchasing and did a full operations walk through with Victim2 on the 16th.  The vessel came with a navigational unit, navigational lights, fire extinguisher, horn, paddle, and a motor stop lanyard.  The vessel did not come with any personal or throwable floatation devices.  
  
  The state of the vessel when it was found was beyond repair, most of the vessels interior was possibly removed by the force of the river.  The throttle was found in neutral and the motor stop lanyard was not attached to the vessel or either occupant of the vessel.  A majority of damage was to the port side of the vessel, so much that the side was crushed in that the cap was separated from the hull.  The engine was in good condition compared to the rest of the vessel, except for the prop having multiple dents and curled edges as if it struck a submerged object.  
  
  The electronic trolling motor on the bow was down and locked into place and it is not known if it was used prior to the accident.  The information leads this investigator to believe that the victims were operating the vessel after sunset on 17th and possibly drove past the boat ramp at Big Slackwater and drove over Dam 4.  At the time of the accident the Potomac River is flowing at a high rate and the normal drop for Dam 4 is approximately twenty feet, but is approximately twelve feet with flooding.  I am unsure who was operating the vessel, but believe that Victim1 may have been thrown from the vessel, because of being found three hundred yards downstream and on the river bank.  The churning of the dam creates an up river draft along the river banks, as far down as three hundred yards.  It is possible that Victim2 was trapped in the rolling water at the Dam base and became dislodged between the 18th and 19th.  With the majority of the damage…