What You Need to Know About Alan Gross

Alan Gross, the American sub-contractor released this morning from a Cuban prison after five years behind bars, says he traveled to Havana to help the island's Jewish population connect to the Internet.

The U.S. government has consistently supported that assertion. But Cuban authorities claim Gross is complicit in "a subversive project of the U.S. government that aimed to destroy the revolution through the use of communications systems out of the control of authorities."

This much is known for sure: The Maryland native, who was 60-years-old at the time of his arrest in December 2009, was working for Development Alternatives, Inc., a Bethesda-based contractor that had recently won a $6 million USAID grant to promote democracy and advance internet access abroad.

How he got to Cuba: He entered Cuba on a tourist visa at least five times in the months prior to his arrest to distribute and study satellite communications equipment - without the permit required by Cuban law.

Gross maintained he didn't understand the perils associated with his job -- but according to the Associated Press, he had acknowledged his work was "very risky business."

How he got arrested: Cuban authorities, suspicious that Gross was conducting espionage on behalf of the U.S., detained him at the Jos Marti International Airport as he was trying to depart, then held him for over a year without charges in Havana's maximum-security Villa Marista prison.

The U.S. State Department denounced the detainment, calling Gross "a dedicated international development worker" who "should be home with his family now."

Nevertheless, in 2011, as three U.S. officials looked on, Gross was tried, found guilty, and sentenced to 15 years behind bars.

What has happened during his incarceration: While imprisoned, he would miss his mother's funeral and his eldest daughter's wedding.

His family "has spent over five years suffering" according to a statement by his wife, who pleaded with the U.S. government to intervene.

What his health is like: In recent weeks, Gross' health has deteriorated dramatically, his lawyer told ABC. The 65-year-old could barely walk due to hip damage and went blind in one eye.

Gross, vowing that he would not endure another year in prison, refused medical treatment and spent 24 hours per day in a 10 by 20 foot room with two other prisoners.

ABC's Jim Avila and Serena Marshall contributed to this report.