According to article dated July 20th, they were just then releasing the information on the computer (B-R). If he threw out the watch box on the 10th, he had from the 10th -- 20th to go back and forth to the "area" Cound have covered the body with more branches, deposited the ring anywhere.
No one would be suspicious of his movement. According to his own aides, "He was in the habit of riding his bicyle through the park."
How far is the B-R from Condit's apartment?
Very very close, practically AT it. Where 31st enters park, near Beach