Some of the employees have declined interview requests, Justice Department investigators say.
More than 20 agencies covered 105,000-square miles searching for the two men, who didn't return from a fishing trip Friday.
The veteran safety has played on three Super Bowl-winning teams in his 9-year career.
"How do you forget your baby?” the mother who was charged with one count of child abuse can be heard saying on the video. Her baby survived.
Eric Garner died in July 2014 after Pantaleo put him in a chokehold during an arrest. The officer was fired from the New York City Police Department on Monday.