This guy Kronk reported that he sighted something suspicious on Aug 11, 12, and 13. When the police finally followed up, it was during the period that the area was under water. The police officer did not go into the water and look. No cadaver dogs were used at that time.
The two affidavits you posted were from October and November of this year. That's pretty late to assume that this was something that the prosecutors were holding back. Are there earlier signed affidavits from these two people?