A man identifying himself as Rubén Darío Grisales testified that he was an eye-witness to the murder and even tried to catch the killer, but he dropped his gun in the pursuit, the killer escaping in the confusion. In a police line-up, the witness immediately pointed out the man he said was the killer, Jorge Iván Obando, who was briefly jailed. But it was then discovered that the witness had used a false name.

State attorney Eduardo Mesa of the Prosecutor´s Office’s Human Rights Unit, decided to interrogate the witness himself and obtained from him a second statement, this time signed with his real name, Juan Carlos Henao. After conducting a number of tests, he came to the conclusion that Henao was in fact the murderer. Henao was a bodyguard and campaign worker for former Congressman Oviedo. Other statements, including one by Alfonso José Jiménez, a member of the police secret investigations division, confirmed Henao’s true identity. Jiménez also testified that several days before the murder police officer Edgar Gamboa had told him that a murder was going to take place for which they would pay 40 million pesos. Gamboa was fired and later was himself killed at a Bogotá nightclub.

Henao is said to have told the state attorney, "If you get me out of this, I’ll tell you how we got the orders to kill Acero Cadena and Jairo Elías Márquez" (who was killed on November 20, 1997). In acquitting Henao, the judge thwarted the possibility of proving that Oviedo had ordered the murder.

Oviedo’s congressional immunity was lifted and the charges against him were sent to the Supreme Court, which hears accusations against legislators. One element in the investigation was the fact that Oviedo founded the newspaper Diario de Colombia in Quindio and had offered Acero Cadena, at the time working at La Crónica in Armenia, a job on his paper. Acero Cadena declined the offer and continued his published criticism of the congressman.