"Like any parent can tell you, your love for your child is unconditional," said de Grood, his wife, Susan, close by his side.
The 22-year-old deGrood has been charged with five counts of first-degree murder in the deaths of Lawrence Hong, 27, Joshua Hunter, 23, Kaitlin Perras, 23, ZackariahRathwell, 21, and Jordan Segura, 22.
De Grood said his son is kind and supportive.
"He had his bright future ahead of him as he was about to start law school in the fall," he said.
De Grood said he and his wife hope to see Matthew soon.
"Just like you, we struggle to understand what happened," said de Grood.
"We have received an outpouring of support from our expended family, friends and coworkers and even people we've never met. We thank each one of you for your support."
De Grood is a 30-year veteran veteran of the Calgary Police Service who has held leadership positions within the force. He is still on active duty.
At a news conference Wednesday, Calgary police Chief Rick Hanson said Matthew de Grood's parents are devastated.
"I talked to the member just before coming down here. He ... asked that I would pass on — he's heartbroken, as his wife is — and he said, 'Could you please pass on to the families our total and complete sorrow and condolences as to what happened?'" said Hanson.
"They feel so much pain for the families that were impacted by their son."