Appeals court weighs admissibility of prior California-assault evidence in Commonwealth v. Sonke

An appeals court panel on Friday, June 6, heard arguments over whether testimony about alleged assaults that took place in California should have been admitted at the trial in Commonwealth v. Sonke, a single-issue appeal that centers on the limits of prior-bad-act evidence.

The question matters because appellate guidance could change how trial courts balance probative value against unfair prejudice when prosecutors introduce uncharged-conduct testimony. Justice Sabida Singh, joined by Justice D'Angelo and Justice Hodgins, presided over the oral argument; the court submitted the case after hearing from defense counsel William Corman and the attorney for the Commonwealth, Kristen Jang.

Defense counsel William Corman argued the California incidents overwhelmed the jury and were unduly prejudicial. Corman told the panel that, although prior-bad-act evidence can be admissible for limited purposes, in this case "at some point, it crosses the line," and he urged the court to adopt clearer boundaries…