ID Help Please!

While I was putting out more seed to lure in birds for the Big Sit! I saw this bird fly over head and I knew immediately it was different. It landed on a tall snag in the creek which gave me great views for several minutes...enough to make these notes and drawings. Can you help me identify it?! I'm still trying out that field-guide-less observation which is really tough, but probably for the betterment of my birding skills. Now that I am back in my office looking at the field guides, I'm afraid to admit what I think it is.

Sorry for the sloppy handwriting and awful drawing, but hey, my fingers were freezing. Here is the translation with post-note clarifications in parenthesis:

In flight dark/wht contrast pattern (on wings), Solitaire-like, Shrike-like, Big hook on bill, calls with kay-kay, About size of a Kestrel, head browner than body, Black line at eye level, slightly below - white at top/back of eye (the black arch I show on the drawing indicates boundary of white near the eye, not a dark mark on the bird), Black wings with white showing, Light tan/gray body, long tail white edges, faint wavy breast, other birds terrified of it, House Finch attacked it.

Other behavior notes - flew over head, perched on snag for several minutes, dove into large shrub after other birds, came back to perch for several minutes, dove into large shrub. I never saw it agin.