Juan Rivera Jr., who spent almost 20 years in an Illinois prison for a murder he did not commit, filed suit on Tuesday against Lake County and several individual officials.

Rivera, now 40, was falsely convicted and imprisoned for half his life, his attorney, Locke Bowman, told a press conference in Chicago.

Rivera was released on Jan. 6 from the Statesville Correctional Center after a DNA test had proved that he was not responsible for the 1992 rape and murder of 11-year-old Holly Staker in the Chicago suburb of Waukegan.

The lawsuit accuses Lake County authorities of having coerced Rivera into making a false confession, of malicious prosecution and of conspiring to deprive him of his constitutional rights.

The case was resolved last December with the examination of DNA collected from the victim's body in 1992, but it was not analyzed until 2004, when it was proved that it belonged to someone other than Rivera.

During the almost 20 years he spent behind bars, Rivera was found guilty three times, in 1993, 1998 and 2009.

After the DNA test, the only supposedly firm evidence linking Rivera to the crime was his confession to Waukegan police, which - according to the appeals judges - had been obtained under coercion.

In the lawsuit presented on Tuesday Rivera claims that on the third day of "abusive interrogation" by the police, he suffered a nervous crisis and was diagnosed with acute psychosis by a doctor working at the jail.

On the fourth day, after 24 uninterrupted hours of interrogation, Rivera signed a confession in English, though his command of the language was shaky.

According to the suit, police knew that Rivera had intellectual deficiencies and a history of emotional problems that made him especially vulnerable to their coercive techniques.

Rivera was 19 years old at the time of his confession and was in jail for a probation violation when he was accused of the murder in an investigation conducted by the Lake County Major Crimes Task Force based on a tip from an informant. EFE