Rte

[GreatWall]

8A: Arrest credited to street cop, apparently, for this kind of crime. (4-6)
9A: Doppelganger (that umlaut means more than one might first see. (10) ????a???e?
10A: Sssss... sounds like something's cooking without a kitchen cooker? yes, without (8)
27A: Will nothing do for such a believer (8) N???????
1D: Get rid of principals? Enlightened lad reach out for bright minds (5-5) ?????-h?a?s
16D Poor place to live and let die in squalor (10-4) D?s???????-????
17D: Isnt this how the hunter bluntly comes to the point (4-2-3-5) ?u??-??-?h?-???s?
26D: Clap for a burst of laughter (4) ??a?

[aelmpvw]

17d cuts to the chase

[elliemay1]

17 answered previously

[Etch]

26D PEAL

[elliemay1]

1D clear heads has been suggested

[sandyRoe]

26 Peal?

[Chaseman]

8a Blue Collar? Although White Collar is in more general usage, perhaps there is also Blue Collar crime?

[Etch]

1D Yes, CLEAR HEADS is an anagram of 'lad reachES'. The 'es' seems to have gone missing.

[elliemay1]

I wondered about the ES!

[elliemay1]

10 barbecue???

[elliemay1]

27 naysayer??

[galma]

27a nihilist