Petithomme goes by the alias Ti Makak, and leads a gang of the same name.
Haiti's National Police did not respond to requests for comment on the police commissary incident or about Ti Makak in general.
Local media reported that Ti Makak was responsible.
But the calls continued, he said, and a group later arrived in person, saying they were linked to Ti Makak.
"We can easily conclude that the Ti Makak band seeks to win the hearts of the people, particularly of those people who have been involved in acts of looting during recent protests," Germain said.