ALBANY – The Court of Appeals split sharply yesterday over whether a defendant was unfairly convicted for stealing a tractor trailer after a record of his involvement in similar but uncharged heists in the past was allowed at his trial.

In a separate ruling yesterday, the Court upheld a trial judge’s decision to exclude testimony that a dentist in a medical malpractice case had malpractice insurance. However, it cautioned judges to question witnesses outside the presence of the jury when such testimony was proposed to minimize the risk of bias.