A 43-year-old pizza chef from Illinois has been charged with first-degree murder over the August 1994 death of 71-year-old Illa Vanard.

Thomas Spear reportedly admitted to the burglary that led to Venard's death and is being held on $3m bail in DuPage County jail.

Spear was first identified as a suspect in Venard's death more than 20 years ago. Assistant State Attorney Kristin Johnson said during a bail hearing that prosecutors were unable to explain why it took so long to charge Spear, who has had run-ins with the law since Venard's death.

Venard, a widow who lives alone, was found dead in her Lisle condominium on the night of 4 August 1994 by her son Keith and his then-wife. An autopsy at the time was unable to determine cause of death, the Chicago Daily Herald reported.

Nearly three years to the day later, on 2 August 1997, a former neighbour of Venard's identified Spear as a suspect.

Police now say Spear broke into Venard's apartment, grabbed her by the neck and shoved her down, WGN9 reported. Venard's checkbook and other items were stolen from the apartment.

The former neighbour told police Spear approached her and her boyfriend, showed them four cheques stolen from Venard and ask them to go cash them with him. Spear disguised himself as an elderly woman, by wearing a red and black scarf and sunglasses, and cashed each of them for $300.

Spear then shared the money with the woman and her boyfriend, Johnson told the hearing. The trio later went on a shopping spree.

Lisle Police reopened the case earlier this year and found Spear in Peoria, Illinois. When found, Spear confessed to the burglary.

He claimed that as he entered the apartment, Venard approached him. Johnson said Spear grabbed Venard by the neck and pushed her to the floor. When she became unconscious, Spear attempted CPR but failed. He then put a chair over her "so he didn't have to look at her".

Following Spear's confession, a medical examiner reopened the case and ruled the cause of death to be cardiac arrhythmia cause by being startled by an intruder. The medical examiner did not rule out strangulation.

Spear is set to be arraigned on 6 November in front of Judge George Bakalis. If convicted, Spear faces a potential life sentence without chance of parole.