Oscar Lopez Rivera, who for decades has been in prison for his role in a Puerto Rican nationalist group connected to terrorist attacks in U.S. cities, will be released on Wednesday.

Former President Barack Obama commuted Lopez Rivera's sentence, which was expected to expire in 2051, just three days before he left the White House in January, allowing the convicted felon to be freed on May 17, 2017.

Now, Lopez Rivera, 74, "will be celebrated as a hero upon his early release" and honored next month in New York City's Puerto Rican Day parade, the Associated Press reported.

Lopez Rivera was originally convicted of crimes committed while he was a member of the Armed Forces of National Liberation, known by its Spanish acronym FALN, a leftist, violent separatist group that sought complete independence for Puerto Rico.

During the 1970s, FALN claimed responsibility for more than 100 bombings across New York, Chicago, Washington, D.C., and Puerto Rico. One of the bombings, at the Fraunces Tavern in New York in 1975, killed four people and injured more than 60 others.

For his crimes, Lopez Rivera was sentenced in 1981 to 55 years in prison for "seditious conspiracy" and other felonies, and an additional 15 years in 1988 "for conspiracy to escape; to transport explosives with intent to kill and injure people; and to destroy government buildings and property," according to CNN.

Lopez Rivera was not charged directly for involvement in FALN attacks, but rather for plotting to overthrow the U.S. government. His prison sentence would have expired in 2051 had it not been commuted by more than 30 years.

In 1999, then-President Bill Clinton offered to commute the sentences of Lopez Rivera and several FALN comrades; Lopez Rivera rejected the offer, however, because two group members were not included.

Upon Lopez Rivera's release, many will welcome him as a beloved son. He will be celebrated across Puerto Rico and Chicago this week, and on June 11, he will be recognized as Procer de la Libertad–National Freedom Hero–during New York City's annual Puerto Rican Day parade.

The FALN member's cause has attracted support from across the left, including former President Jimmy Carter and Sen. Bernie Sanders (I., Vt.), who have backed Lopez Rivera.

"One can disagree or agree with him politically, but he is a symbol of resolve and conviction," said Lin-Manuel Miranda, the creator of the hit broadway musical "Hamilton," who tweeted that he was "sobbing with gratitude" after Obama commuted the sentence.

Many Puerto Ricans also celebrated Lopez Rivera.

"We have to thank him for giving his life for our island," Nelson Cortes, a 45-year-old waiter who supports Puerto Rican independence, told the AP. "It's exactly what we need right now."

But victims of FALN's bombings feel differently.

"I've had long hours in the middle of the night trying to figure out what I am missing, why he has all this support," Diane Berger Ettenson said of Lopez Rivera. Ettenson was six months pregnant when her husband was killed at Fraunces Tavern.

"Every time I have to defend my father's life, it takes a little more of my life away," said Joseph Connor, who was 9 when his father was killed, also at Fraunces Tavern.

"My kids never met my dad, but they certainly had to deal with this. We never asked for it."