ELGIN, Ill. (CBS) — An 84-year-old Elgin woman with a long rap sheet for drug arrests ran the risk of spending the rest of her life in prison for cutting a police officer’s index finger.

But a judge gave her a sentence that involves no prison time at all.

Following a bench trial, Kane County Judge David Akemann on Tuesday found Rosella Robinson not guilty of the most serious charge against her – aggravated battery to a police officer. Because Rosella has a felony rap sheet, she would have faced a minimum of six years in prison if convicted.

But the judge did convict Rosella of misdemeanor resisting arrest.

After a quick negotiation between the opposing attorneys, Akemann then sentenced the grandmother to perform 100 hours of community service and endure 12 months of conditional release, a probation-like status in which the convict’s main obligation is simply to stay out of more trouble.

The charges grew out of an incident on the afternoon of July 18, 2011, when Elgin police Officer Anthony Rigano interacted with Robinson as she sat in a car along Percy Street. Rigano went away with a bleeding 1-inch cut on his left index finger.

Both Rigano and Robinson agreed the finger became cut while Rigano was reaching into Robinson’s car to remove her car key from the ignition. But Rigano testified during the trial this past Friday that Robinson swatted at his arm and scratched him with her fingernails to keep him from removing the key.

Testifying Tuesday, Robinson denied scratching or swatting him. She said he probably cut his finger on a piece of wire she claimed had been attached to the key ring.

The two’s testimony also differed about what had led up to the confrontation. Rigano said he became suspicious of the car because a license plate check showed it was registered to a woman (Robinson’s granddaughter) who was known to associate with a fugitive. Rigano said he got the legal opportunity to stop the car when Robinson drove away from the curb without using her turn signal and made what he described as an unsafe U-turn.

But Tuesday, Robinson claimed she never started driving away. She said she had just been sitting in the car, ”doing nothing wrong,” when Rigano came up, started asking questions about the fugitive, and asked for her driver’s license and car key.

In his closing arguments, Assistant State’s Attorney Jonathan McKay said that although Rigano’s wound was minor, “it was bloody. It was hurting, It was cut. That’s all you need to (show the defendant) caused bodily harm.”

Because the victim was a police officer, it would be considered an “aggravated battery.” And because Robinson has several past convictions — including a five-year prison sentence for delivery of a controlled substance when she was 69, and a guilty plea for possession of a controlled substance when she was 80 — if the judge had convicted her of aggravated battery, he would have been required to sentence her to from six to 30 years in prison.

McKay described Robinson’s time on the witness stand as “ridiculously un-credible testimony that changed multiple times.”

Robinson perhaps also lost some credibility with the judge when she became so angry while being cross-examined that Akemann cautioned her, “Ma’am, lower your tone.”

Taking no time off the bench to deliberate, Akemann announced his verdict without any detailed explanation of his thinking, except to say that the prosecution had failed to prove the aggravated battery charges beyond a reasonable doubt.

Before that announcement, however, Akemann noted that “everyone is treated equally (under the law) in some sense. But I’m sure the officers would testify that they treat the elderly and children differently than middle-aged adults, for instance.”

The Elgin Courier-News contributed to this report, via the Sun-Times Media Wire.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)