A newly surfaced video is adding another potentially important piece to the Nolan Wells investigation — and investigators may now have more visual evidence to examine from the critical hours before the 18-year-old disappeared from Horn Island.

The footage reportedly captures activity around the boats on July 4, the same day Nolan traveled to Horn Island with friends. One video appears to show a boat that may match the vessel associated with Nolan’s group, while another piece of footage has drawn attention because of the possibility that a person seen aboard could be Nolan. However, the identity of the individual has not been definitively confirmed.

The timing of the footage could be especially important. Publicly reported evidence places Nolan’s group on Horn Island during the afternoon, while investigators continue trying to reconstruct the sequence of events leading up to the period when Nolan was last accounted for.

Another video that surfaced later appears to show several people aboard a boat as it was being prepared to leave the island, with Nolan reportedly not visible in the footage. That has raised renewed questions about exactly when he separated from the group and what happened during the remaining window before he disappeared.

Now investigators face a crucial question: Can the various videos, photographs, GPS records and witness accounts be placed into one verified timeline?

GPS data obtained by CBS News previously showed the boat carrying Nolan left the mainland at approximately 9:56 a.m. and arrived at Horn Island around 11:14 a.m. on July 4. That provides an independently documented starting point for reconstructing the day’s movements.

The investigation has also drawn attention to a 4 p.m. emergency towing call made from a boat on Horn Island. The recording was released by the Mississippi Department of Marine Resources, and Nolan’s family’s attorney has said audio experts will examine it for potentially relevant information. Experts have cautioned that interpretations of unclear background audio should not be treated as established facts without proper forensic analysis.

Taken together, the emerging video evidence, GPS information, witness accounts and emergency-call recording could become important in resolving the timeline surrounding Nolan’s final hours.