KCPQ (FOX) is based in Tacoma and is owned by the Tribune Company.
Also, some speculation. Apparently the "security" included receptionists "ringing in" persons - sounds like no free front door access.'
And there was a "blond woman" just outside the door on the curb, injured.
My bet is the perp waited for someone to normally exit the office to gain entry.
I don't know where you get your information. Ch 13 was located in Tacoma a number of years ago, but have been in Seattle now for a good long time. Their studios are right on Lake Union, which is a far cry from being anywhere near Tacoma, and is pretty much downtown Seattle.
I REPEAT- KCPQ Ch 13 Fox affiliate is located in downtown SEATTLE, not Tacoma.