(AP) — Jury selection is starting in the second-degree murder trial of a Florida neighborhood watch volunteer charged in the fatal shooting of an unarmed teen.

The trial begins almost a year and a half after George Zimmerman fatally shot 17-year-old Trayvon Martin.

The first day of jury selection is Monday. Zimmerman is pleading not guilty, claiming self-defense.

The judge in the case also must listen to final testimony, and then rule on whether voice recognition experts can be allowed to testify at trial.

Pretrial testimony on whether experts could determine if Martin or Zimmerman were screaming for help on 911 calls took three days last week, but the matter is still unresolved.