(NewsNation) – Earlier this week, U.S. Marshals released age progression footage of convicts who escaped from Alcatraz Island more than 60 years ago.

Over the years, speculation has grown as to whether the escaped prisoners are still alive or not.

Clarence Anglin, John Anglin and Frank Morris remain wanted fugitives for their escape from Alcatraz on June 11, 1962, where they were serving time for armed bank robberies.

“They are unlikely to be alive,” said Michael Dyke, the former chief investigator of the case, during a Wednesday appearance on “NewsNation Prime.” “Even at their advanced age it is unlikely (that) if they survived the escape that they would be alive. My guess is that they did not survive that first night.

The three men spent over a year organizing and planning their escape, setting up a secret workshop above their cells, and stockpiling the tools and resources needed to make the dangerous journey.

Dyke said the escapees left at the worst possible time due to ocean currents and it’s unlikely they even landed.

It was however reported that the escapees launched a makeshift raft made up of more than 50 raincoats, and there were tales of car theft on the night of the disappearance.

Dyke said it was possible a raft like this could have worked, but one of the escapees would have had to constantly inflate the raft while the other two paddled.

“As for the missing car, it was reported a day or two later by someone (saying) that the car had left the road. They said it was occupied by at least two people. says it may have been stolen from Marin County. There’s actually no way, right now, to go back and verify all of this because all of these records have been purged,” a said Dyke.

In 2013, authorities received a handwritten letter from a man claiming to be John Anglin, asking for a light sentence in exchange for medical treatment.

Dyke carefully examined the letter and said the handwriting was not even close to replicating the handwriting of the escapees.