Robbins, 44, was convicted of shooting a man in 2002 in Indiana when the man tried to intervene in a fight Robbins was having with his wife.
The dead man, Rutland Melton, scolded Robbins telling him he should not hit a woman. Robbins shot Melton in the chest.
Robbins was brought to Chicago to appear in court for an unrelated drug case, but when that case was dropped, Robbins was released rather than being sent back to Indiana.
The Cook County Sheriff's office has asked for the public's help in locating said Robbins, a native of Gary, Ind.
He is described as a black male, around 5-feet-5 and 190 pounds, with a tattoo on the right side of his neck that says "Nicole."
The sheriff's office has launched an investigation into Robbins' mistaken release.