He is a Canadian actor, born on November 30, 1998. He completed his education at Simon Fraser University. He began his acting career as a child. His debut was in The Secret of the Nutcracker (2007). He is known for Liz (2011), Diary of a Wimpy Kid (2010), and The Imaginarium of Doctor Parnassus (2009). Among his many awards and nominations, he received a Young Artist Award for his role in Liz (2011) and two Leo Award nominations. His prosecution for the murder of his mother on March 31, 2020, started in June 2022. He admitted during the trial that he also meant to assassinate Justin Trudeau, the prime minister of Canada. Grantham received a life sentence after being convicted of second-degree murder. However, 14 years after he started serving his term, he will be qualified for parole.