Luigi Mangione Sketch Artist Says He Finally Showed Emotion in Court While Pleading Guilty

Luigi Mangione seemed to finally feel the full weight of his crime in court, becoming emotional during the proceedings ... so says the sketch artist.

Christine Cornell -- who has sketched Luigi numerous times during his legal journey -- said on CNN he's always seemed distant in the courtroom ... listening intently to the hearings but not conveying any feeling.

She likens him to a husky ... a beautiful dog -- but it's impossible to tell exactly what they're thinking.

However, she says today -- while admitting to killing UnitedHealthcare CEO Brian Thompson and pleading guilty to federal stalking charges -- she says he finally showed all of the emotion he'd seemingly been hiding.

Christine says Luigi's voice shook and -- though he didn't cry -- he looked close to tears.

The CNN host Erin Burnett asks Christine if he could've been playing up the scene for the judge in order to possibly get a lighter sentence down the line ... but she shoots down the theory -- telling the host she's certain his emotions were genuine.

As you know ... Luigi pled guilty to federal stalking charges -- without a deal with prosecutors in place. He's essentially throwing himself at the mercy of the court and hoping for a less severe sentence.

Federal sentencing guidelines state Luigi should receive between 24 and 30 years ... and a judge has already stated he will need to serve 85% of his sentence. If given 24 years, Luigi could be out in 20.

At least one of Brian Thompson's family members -- his uncle, Bruce Thompson -- told The Times he wants Luigi to "get what he deserves" adding the family wants the judge to hand out the maximum sentence possible.