In announcing their progress on the probe into attacks on two places of worship, authorities pushed for the case to be prosecuted as a hate crime.
"The fact that the incident took place four days after the tragedy of 9/11 in 2001 and the two places of worship that were targeted by the accused parties were a mosque and a Hindu temple, the Hamilton Police Service will present this case as a hate crime," police said.
The incidents changed the city forever in a "profound way" as it focuses on "inclusivity, respect, tolerance and understanding," said Police Chief Glenn De Caire.
Authorities had originally focused their investigation on two male suspects but both were later cleared of involvement.
This year, police received new information from the public and through witness statements and DNA profiling were able to link the accused to the attacks on both the mosque and the temple.
Christopher Pollard, 33, Scott Ryan, 33, and Damien Marsh, 34, all of Hamilton, are all charged with arson to property, possession of incendiary material and mischief under $5,000.
Flames broke out at the Samaj Temple on Hamilton mountain early on a Saturday morning just four days after co-ordinated terror attacks on New York and Washington destroyed the World Trade Center.
The temple, which at that time served about 800 people, was located near a mosque that had been vandalized hours earlier after receiving a hate message on an answering machine.
In the earlier incident, a large front window of the Hamilton Mountain Mosque had been broken, causing less than $5,000 in damage.
The fire at the temple, which started at the front doors, engulfed the entire building and caused about $500,000 in damage.
No one was injured in the massive blaze which required 13 fire vehicles and two portable water tanks to fight the flames.
The fire marshal's office concluded an accelerant was used to light the fire and classified the incident as arson.
At the time, the temple fire was considered the worst act of vandalism against a Canadian house of worship in the wake of the Sept. 11 suicide attacks.
While 10 mosques and three synagogues in Canada saw windows broken and spray-painted with messages of hate in the backlash following 9/11, all that remained of the temple after the fire was its hand-carved entrance.
Police had said at the time that the arsonists likely confused the temple with a mosque.
While the loss of the temple devastated Hamilton's Hindu community, it also brought together people of different faiths.
Members of just about every church, synagogue, mosque and Sikh gurdwara in the area came out to help the Hindu community raise the funds needed to rebuild the temple.
Investigators said Wednesday they believe there are people who know more about the incident and are asking them to contact police.