He hated religion. He hated rule breakers. He hated people who parked in his spot.

The man at the centre of a case that caused a worldwide furore four years ago over anti-Muslim violence was filled with so much hate that he shot and killed three of his neighbours, all students of Middle Eastern descent, at his apartment complex in Chapel Hill, North Carolina.

The man, Craig Hicks, pleaded guilty on Wednesday and is expected to receive three consecutive life sentences for murders that police initially said stemmed from a parking dispute.

Even so, the case has tested the limitations