It's part of a pattern of islamophobic hatred directed at that particular Quebec City mosque.

In June, 2016, the severed head of a pig with a note saying "Bon appétit" was left at the mosque. 
 
In January, 2017, the fatal killings.

In July, 2017, a package was delivered containing a defaced Qur'an and a note suggesting they use a hog farm for their cemetery.

In August, 2017, the president of the mosque had his car firebombed. No arrests have been made.