Matthew de Grood has been charged with killing five young adults at a Calgary house party.

Five people — four men and one woman, all in their 20s — were killed in the attack that started around 1:20 a.m. MT.

The victims had been attending an end-of-year university party in the community of Brentwood, which is just north of the University of Calgary campus.

De Grood is 22 years old. He faces five counts of first-degree murder. Here is what we know about him.

His dad is a veteran police officer

De Grood is the son of a veteran Calgary police officer. Insp. Douglas de Grood has spent more than 30 years with the service and has held several leadership roles.

Calgary Police Chief Rick Hanson told CBC News that 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?'" he said.

"They feel so much pain for the families that were impacted by their son."

Hanson said the family has been extremely co-operative with the investigation.

He was treated for a dog bite

Police say the suspect fled on foot but an arrest was made about 40 minutes later with assistance from the K-9 unit.

Investigators say they are not looking for any more suspects.

He was taken into custody after a struggle with police.

De Grood was taken to hospital to be treated for a dog bite.

Matthew de Grood was taken to hospital to be treated for a dog bite after Calgary police arrested him with the help of the K-9 unit Tuesday morning. Calgary police say the son of one of their own is a suspect in the worst mass murder in the city's history, a bloody and baffling attack on a group of five young adults at a house party. (Global News/Canadian Press)

He was a pre-law student

De Grood, who attended the University of Calgary, was planning to attend law school.

He was also tagged in a Facebook post that said he graduated with a bachelor of science (major in psychology/minor in law and society) with distinction in June 2013.

De Grood was currently working at a grocery store not far from where the killings took place this morning.

He graduated from Calgary's St. Francis High School in 2009.

He had no history with police

The attacks happened shortly after de Grood arrived at the party, according to police.

“The suspect arrived at the party, obtained a large knife and targeted the victims one by one, stabbing them,” said Chief Hanson.

He, along with the victims, have no history with the police. Drugs and alcohol are not considered a major factor in the attack.

"At this time, we can't say the exact why," said Chief Hanson.

​The suspect had a weapon — which police referred to as "an instrument" he brought from work — but investigators believe the primary weapon was from inside the home.

Police say multiple witnesses are currently being interviewed by detectives.

A police investigator examines a knife on the street near the scene of a multiple fatal stabbing in northwest Calgary. (Larry MacDougal/Canadian Press)

His last Facebook post

At 5:39 p.m. MT Monday, de Grood posted "Dread and the fugitive mind - the world needs a hero."

The message is related to a Megadeth song called Dread and The Fugitive Mind of the album The World Needs a Hero. The full lyrics are posted below:

Let me introduce myself I'm a social disease

I've come for your wealth leave you on your knees

No time for feeling sorry, I got here on my own

I won't ask for mercy, I choose to walk alone

What's yours is mine and what's mine is mine too

If you shake my hand better count your fingers

What if I do get caught? What if there is no judgment?

If I'm right I lose nothing, if you're right I lose it all

I ought to get caught because I'm doing something wicked

I'm guilty haunted by my fear and the only consequences

Are Dread and the Fugitive Mind

You built walls to protect you so no one will infect you

Pursued by those out there that vanish in thin air

Come a long way to find what you really left behind

You don't know when the end is but it's coming fast

What's yours is mine and what's mine is mine too

If you shake my hand better count your fingers

What if I do get caught? What if there is no judgment?

If I'm right I lose nothing, if you're right I lose it all

I ought to get caught because I'm doing something wicked

I'm guilty haunted by my fear and the only consequences

Are Dread and the Fugitive Mind