The final defendant pleaded guilty to an attempted robbery charge related to a shooting and botched robbery that left a Park Ave. resident with a gunshot wound in November.

The final defendant pleaded guilty to an attempted robbery charge related to a shooting and botched robbery that left a Park Ave. resident with a gunshot wound in November.

Austin Anderson, 16, of Hannibal, entered his plea before Judge Rachel Bringer Shepherd on Monday, July 3, in the Marion County 10th Circuit Courtroom. Special Public Defender Raymond Legg represented the defendant. Marion County Prosecuting Attorney David Clayton represented the state. The Class B felony of first-degree attempted robbery carries a punishment range of between five and 15 years in prison.

Anderson’s charge stemmed from a Nov. 20 botched robbery at Ronald Gillum Jr.’s home at 1737 Park Ave. Court documents alleged that Willemarck, John Newman and two co-defendants — Willemarck’s younger brother Anderson, and Stephanie Pettitt — planned to rob Gillum. According to the probable cause statement, Willemarck and Newman armed themselves with guns, while Anderson carried a “baseball bat type” object and Pettitt acted “as a look out.” Newman knocked on the door and shot Gillum in the abdomen after the door opened. The robbery attempt was foiled when Gillum managed to close the door. The four fled the scene.

Three co-defendants, including Anderson’s older brother, Thomas P. Willemarck III, of Hannibal, have already been sentenced in the case. Willemarck was sentenced to a 120-day Department of Corrections treatment program, and he would serve a 10-year prison term if he failed to complete the program. John Newman pleaded guilty to felony charges of attempted robbery, armed criminal action and second-degree assault. He received a 15-year prison sentence. Stephanie Pettit, who allegedly served as a “lookout” during the robbery attempt, received probation for her cooperation against the other defendants in the case.

Anderson will appear for a sentencing hearing at 9:30 a.m. Monday, Aug. 21, before Judge Shepherd. The defendant remains lodged in the Marion County Jail on a $100,000 cash-only bond.

Reach reporter Trevor McDonald at trevor.mcdonald@courierpost.com