Section 2:
-P1: Her gaze fixed? On…something different? Or why mention it again? I’d maybe combine some of the essential elements in this second descriptory (yes, I’ve invented a word) sentence with the first one. Something like: “Calmly pretending to wash the dishes, Sue peered out the ground floor window, her gaze fixed upward on the square of lighted glass that marked one of the neighboring house’s bedrooms.” Or to keep nearer the latter half of your sentence’s original wording: “…Sue peered into the outer nightscape, and up toward the neighboring window.” Either way, I’d find a way to avoid using “window” twice in the same sentence since you’re describing separate objects.
-P2: I already hate Greg and it’s just the first sentence. Too many “ings.” Now I *really* hate Greg. More specific word than “moved”? “Moved” works here alright, but he could stomp or skulk or slouch or stalk or…wow, that’s a lot of “s” words…plod?
-P3: Love the physical transfer of Sue’s focus.

Section 3:
-P1-3: Teeheeheehee. An excellent section overall. Except who is it that says “Shit?” The scene implies that it has to be David; he’s the only one in speaking distance. But why would he say “shit” to a friendly wave? However, I like the way it almost seems to answer the prior statement: They all knew what was going on here = shit.
-**Cosmetic thing: “lamplight” can legitimately be one word, and I think it looks better that way on the page. On that note, “lamppost” is legit too, but looks kind of funky; I tend to hyphenate it.

Section 4:
-P2: Excellent description of the glass!
-P3: If there was screaming, why would they still think it had something to do with David’s history of “indecent” exposure? Spell out “Street.” Also, police officers refer to things in code. They wouldn’t say “possible break-in.” They’d say “We have a 4202” (or something similar; you can probably find the actual code online somewhere).

Section 5:
-P2: Here’s that word “peer” again. It’s one of those verbs that people tend to remember, so in a section this short, you can really only use it once. Also, for some reason I remember body bags as being typically black in color (to hide blood and other fluids, I think). I could be wrong about this.
-P3: His bare feet “brought,” not “bringing.”
-P6: You’re missing a verb in the second phrase of this sentence. The way this reads now implies Eric was already with David and is mimicking his movements, and that the panicked expression is on David’s face, not Eric’s.
-P7: Nice, tight dialogue. Introduces new plot point well.
-P8: Watch the excessive “ing”-ing. More “ed”s. Hints in dialogue and action make me wonder what kind of relationship these guys have… Regardless, we never really get a good description of either man. Rough age? Height? Build? But worked craftily into the story, of course.

Section 6:
-P1: Yay Maglite! Except you spelled it wrong! But way to use something much more descriptive than “flashlight.”
-P2: Oh. Here you use “flashlight”. Shame, shame. How about affectionately referring to it as the “Mag” instead? Try saying “three parallel five inch long lines” aloud. Now say it faster. Now think about trying something like this “three parallel lines, each roughly five inches long…” Final sentence of that paragraph needs a semicolon is place of that first comma (I know, I know. I said I was done with the punctuation harping. Obviously, I lied.)
-P3: I don’t see how that question’s particularly rhetorical. Claw marks that big aren’t a usual thing to come across.
-P4: Combine middle 2 sentences with a comma, and “lining”  “lined”. Wonderful final descriptory sentence!
-P5: What now? An excellent question, and one I would very much like the answer to.

Final Comments:
-Strong start to an interesting story. I really hope you keep going with it, or I’m going to start hounding you until I at least know what the heck escaped from the Gibbsons’ home. And also how whatever-it-is got there.
-As I’ve mentioned before, beware of overusing “ing” verbs. Also, watch the commas. Some are necessary, some aren’t.
-Most of your characterization is done through internalized thought. We get a good sense of the person behind David and the two Gibbons as well, but little of their external appearance.
-How’s that for a general commentary of Ch. 1?