Royal Oak Sushi House Murders and Angus David Mitchell

Came across this tragic story from last year and wondered if there had been any new information released by the police? I found some scattered updates from news articles but nothing that reveals anything about motive.

The victims were:
Huong "Andy" Tran (owner), father of two young sons
Chinh "Vivian" Diem Huynh (employee), single mother of young daughter

The killer, Angus David Mitchell, was a psycho who had a hit list of people and business (including schools).

Burnaby:
- restaurant (Royal Oak Sushi House)
- person (Mitchell's former landlord)
- school

Vancouver:
- coffee house
- person (Chinh Diem Huynh)

New Westminster:
- person

Coquitlam:
- person
- landscaping business

Port Coquitlam:
- person

Surrey:
- group home
- restaurant
- gym
- school
- person

White Rock:
- security business

It went beyond a list of names, apparently he had detailed information on each target, their schedules and where they lived with planned escape routes.

He was arrested in Saanich for bringing a gun into a doctor's office but Victoria PD returned it to him. After the restaurant homicide, he shot and wounded his former landlord before being gunned down by police in Maple Ridge.

From his facebook:

 

Seems like he need medical help..

 

No doubt. I think Victoria PD messed up majorly by giving back his firearms. The homicide victims were very nice people and hard workers. I'm puzzled over what kind of beef he would have had with them.

Maybe he used to be an employee but got fired? Unrequited love with the restaurant employee?