TORONTO -- A co-worker of Nathaniel Veltman, the suspect charged in the attack on a Muslim family that left four members dead and a nine-year-old boy an orphan, is troubled that he may have missed warnings.

“Looking back on it, seems maybe there was a little bit of something there, but I never thought much of it,” the co-worker, who does not want to be identified, told CTV National News' Omar Sachedina on Friday.

The attack killed Salman Afzaal, 46, his wife Madiha, 44, their 15-year-old daughter Yumnah and Salman's 74-year-old mother while they were out for a walk in northwest London last Sunday.

Fayez, the family’s nine-year-old son, survived the attack but was seriously injured.

The co-worker and Veltman were both employed at an egg-packing facility in Strathroy, Ont.

Veltman made the odd comment about Muslims that suggested he was “suspicious” of them, the co-worker said, but nothing to suggest a potential for violence.

“He thought they were different people,” he said. “He thought they weren’t peaceful like they claim to be.”

Veltman faces four counts of first-degree murder and one count of attempted murder. None of the allegations has been proven in court.

Watch the interview with the co-worker attached to this article.