Prosecutors alleged that Angulo (commonly known as “The Invisible Man”) ordered the killing while serving a 54-month sentence in a Quito prison on firearms charges.
He denied the charges, claiming he was a “scapegoat” for the murder.
Castile was put in charge of logistics for this murder case. She is said to have supplied the murderers with weapons, money, and motorcycles.
Others, Eric Ramirez, Victor Flores and Alexandra Chimbó, are accused of helping the hit squad track Mr. Villavicencio's movements.
More than 70 people testified at the trial, including one key witness who said the gang had been offered more than $200,000 (£154,000) to kill Mr Villavicencio.
Mr. Villavicencio, a leading activist in the fight against corruption, was one of the few candidates to have alleged links between organized crime and government officials in Ecuador.
In the weeks leading up to the election, the politician received death threats and was given security. But he continued to campaign and on August 9, he was shot by a group of assailants outside a school in northern Quito.
Prosecutors said at trial that one of the men involved in the assassination was shot dead in a standoff with police at the scene.
The remaining six men (all Colombian nationals) were later arrested in connection with the murders, but were later found murdered in El Litoral prison while in pre-trial detention.
Prosecutors said a separate investigation into who contracted with Los Lobos to carry out the assassination is still ongoing.
Mr Villavicencio's widow, Veronica Sarauz, welcomed the verdict. But she said it was just the beginning of a long journey to uncover the full story of her husband's death.
Ecuador has historically been a relatively safe and stable country in Latin America, but in recent years, crime has surged as Colombian and Mexican drug cartels have gained influence and infiltrated local criminal organizations.
The Los Lobos gang, led by Angulo, is known to have close ties to Mexico's powerful Jalisco New Generation Cartel.
