António Luís Costa

Costa's trial began on July 4, 2007; he was charged with three murders, three crimes of hiding the body, one crime of profaning the body (for undressing a body), two crimes of attempting sexual coercion, and one crime of calumnious denunciation (for accusing Lourenço's uncle of the crimes). During the trial, Costa claimed his innocence and remained silent except for the first and last court sessions.

On July 31, 2007, the court found Costa guilty of all charges except for the crime of hiding Isidoro's body, since she was still alive when she was thrown into the Atlantic Ocean. Costa was sentenced to 64.5 years in prison, reduced to 25 years, the maximum penalty under Portuguese law. His defense announced they will appeal the conviction.

Costa was arrested by the Polícia Judiciária (PJ) on June 24, 2006. At first, he confessed the crimes, both to the police and to the judge conducting the preliminary investigation. He later withdrew his confession and accused an uncle of Lourenço for the crimes. He claimed police coerced him into confessing, an accusation refuted by the PJ. Costa's telephone was tapped, and he was recorded confessing the crimes to his family.

Costa's first victim was Isabel Cristina Isidoro, who went missing on May 24, 2005; her body was recovered from the ocean on May 31, 2005. Mariana Lourenço went missing on October 14, 2005, and her mutilated body was found in June 2006. The third and last victim was Joana Oliveira, who went missing on May 8, 2006; her body was recovered from under a bridge based on directions given by Costa. According to Costa, after he had consensual sexual relations with the first victim and asked for a kiss from the second and third victims, he suffocated them when they threatened to tell.

António Luís Costa (born 1953) is a Portuguese ex-GNR soldier and serial killer from Santa Comba Dão. He was convicted in 2007 for the murders of three young women between May 2005 and May 2006. He is currently held in the prison of Évora. The case received extensive media attention in Portugal. It was front page in some newspapers.