Leopoldo Lopez, a prominent Venezuelan opposition leader, reappears in public

In 2015, Leopoldo Lopez, a prominent opposition leader in Venezuela, vanished from public life when he was convicted of inciting violence during deadly nationwide protests and sentenced to more than 13 years in prison.

On Tuesday, he reappeared. In a video posted on Twitter, he stood behind Juan Guaido, the country’s self-declared interim president, who urged the military to join his effort to oust President Nicolas Maduro.

Lopez told reporters that he had been ”liberated” by members of the armed forces. His freedom was seen by some as a sign that Maduro’s hold on the military has been diminished and as a potential turning point in a three-month standoff over who leads Venezuela.

“It really said something about the fact that there is a clear break in the military,” said Dany Bahar, a Venezuelan economist at the Brookings Institution think tank in Washington.

He said that without the loyalty of the military, Maduro would almost certainly be forced from power.

The reemergence of Lopez came amid massive protests in Caracas on Tuesday in which Guaido called on the armed forces to abandon their support of Maduro.

Chile’s foreign minister tweeted Tuesday that Lopez and his family were staying as “guests” in the country’s diplomatic mission in Caracas, but later said they moved to the Spanish Embassy because other people were already staying in the Chilean quarters.

Lopez, who is 48 and has a degree from Harvard’s school of public policy, comes from an elite family with a long history in Venezuelan politics. He has been a key opponent of the leftist governments that have dominated the country since Hugo Chavez came to power in 1999.

A former mayor of Caracas’ Chacao borough, he helped found the Justice First party in 2000 to challenge Chavez, then started the Popular Will party to take on Maduro, who became president in 2013 after Chavez died.

Lopez paid for his activism. He survived several assassination attempts, including a 2006 shooting that killed one of his bodyguards, who was sitting in a passenger seat normally occupied by Lopez.

That same year, Lopez was charged with 26 criminal counts, including illegal campaign financing. He denied the allegations but was disqualified from running for public office until 2017.

His conviction in 2015 for inciting violence in protests the previous year was heavily criticized by foreign governments and human rights groups, including Amnesty International, which considered him a “prisoner of conscience.”

He was released from prison in 2017 but placed under house arrest.

Shannon K. O’Neil, a senior fellow at the Council on Foreign Relations, said the government’s repeated attempts to silence him reflected the threat he posed to its rule.

His presence in the video, which by Tuesday afternoon had more than a million views on Twitter, was a “striking image,” she said.

“He has become this crucial opposition leader,” she said. “Even after years of military imprisonment and house arrest, he’s still central to the fight against Maduro.”