Friends and family of Nathan O'Brien held a private memorial for the Calgary boy missing since late June.

Calgary police believe the five-year-old was killed along with his grandparents Alvin and Kathy Liknes.

​​Douglas Garland, who had connections to the Liknes family through his sister and onetime business dealings with Alvin Liknes, has since been charged with three counts of murder in the case.

The memorial was held at a Calgary church Thursday morning and had more than 200 people in attendance.

Many of them were wearing Spiderman T-shirts and other costumes in honour of the boy, whose parents fondly remember him as their "superhero." 

Rod and Jennifer O'Brien called him that when they made a public plea for his safe return in early July.

O’Brien was remembered as an active child who loved life, enjoying every day to the fullest.

"Nathan’s family would like to express their heartfelt thanks and gratitude for all the thoughtful expressions of love and kindness by relatives and friends, during their time of loss and bereavement,” the funeral program read.

There will be a separate memorial in the coming weeks for Nathan's grandparents.

A trust fund has been established to help the family. Donations to the O'Brien Fund can be made at CIBC branches across the country.