The Michigan Supreme Court heard arguments Thursday about critical jury instructions in the second-degree murder conviction of a man who fatally shot a 19-year-old unarmed woman on his porch in suburban Detroit.

A jury in 2014 rejected Ted Wafer's self-defense claim and convicted him in the death of Renisha McBride in Dearborn Heights.

Wafer is white and McBride was black, and some wondered in the aftermath of the 2013 shooting whether race was a factor, likening it to the shooting of Florida teenager Trayvon Martin. But race was hardly mentioned at trial.

Wafer, however, said his rights were violated when Judge Dana Hathaway rejected a specific jury instruction. Wafer wanted her to tell jurors that he shot McBride because he believed she was trying to break into his house — a key distinction under Michigan law.

"It's a thumb on the scale that the Legislature intended as extra protection," Wafer's attorney, Jacqueline McCann, told the court.

"He did not get that extra protection, that extra layer that would have told (jurors) that even though she was unarmed and a 19-year-old girl, he was, under the law, allowed to assume that someone was trying to come in to kill him," McCann said.

McBride was drunk and had crashed her car hours earlier. She somehow ended up at Wafer's house at 4:30 a.m. Prosecutors said she probably had a head injury and was confused.

Wafer, now 58, said he was awakened by pounding and feared for his safety. He opened his front door and shot McBride through a screen door.