An LGBT rights activist, Mantilla was arrested in May 2014[2] during the 2014–15 Venezuelan protests against the government of Nicolás Maduro.
On November 11, 2016 it was reported that he was transferred to the Military Hospital because of a delicate health condition.
[5] A few months earlier it had been reported he had gallstones and was very ill.[6] On November 15, 2016 his mother, Ingrid Flores, reported he had been transferred once again but this time to the Urólogico San Román to treat a stomach infection that was affecting his pancreas.
[2] In an interview with the digital site Panorama he said he would take a few days off to be with his family and was quoted as saying, "I am filled with hope and my commitment to Venezuela is stronger than ever.
I will continue to fight for human rights and to achieve freedom for Venezuela and other prisoners of conscience.