i've noticed the scenes  where  his sketches are shown; his 'killer bob' was masterful. is the actor himself an artist? or had the sketches he was shown 'drawing' been executed by someone else beforehand?

Pretty sure that Harry Goaz DIDN'T do the sketches himself.  In fact, there's a continuity error, as someone (Lucy, I think) identifies Hawk as their sketch artist, then Andy is substituted. Of course, they worked this for comic potential later, when Andy sketches the back of Leland's head at his hearing...
 

I think the only time Lucy says that Hawk does the sketches is during the extended Euro ending of the pilot.  And since that is all pretty much throwaway anyhow... (yes, Hyde!) ...it's not exactly a continuity error.

I've never liked his Leo Johnson sketch though... And BTW, I've never understood why they didn't show Ronette a photograph instead of a sketch...

I always thought they showed Ronette a sketch instead of a photo,because they just wanted to make sure she would recognize Leo ,maybe Cooper just wanted to be sure...Ronette was the only witness and after all she was in a coma...they supposed she would probably have mental problems,caused by the shock she had to experience....at least that's what I think...could be wrong:) and btw I don't like the Leo sketch,either...

It's what I thought I saw when I first glanced at it. 

spoilers

From episode 2: Coop: "Hawk sketched his picture," referring to the full dream that we didn't see (a rough intl. pilot sketch).

Plus Ronette was in a poor mental state, thus she recognized BOB. Although that's technically the real culprit, it's not what they need.

thanx for the info re henry goaz.[lol, thankyou for telling me the actor's name who'd played Andy.]

Harry.  

I thought he might have been artistic, since he had such a high brow.

Hsrry Gost R.I.P.