SIGNS OF A METH LAB
Chemical Smells
A telltale sign of a meth lab is a powerful chemical smell. The odor of an active meth lab may smell like:
Paint thinner or vanish smell
Ether or a "hospital smell"
Sour or vinegary smell
Ammonia-like smell (like the smell of window cleaner, fertilizers or even cat urine)
Equipment
Meth labs are usually equipped with items such as:
Pyrex, glass or Corning containers, mason jars or other kitchen glassware (These may be fitted with hoses, clamps, or duct tape.)
Plastic soda bottles (This may be the only evidence of meth labs that use the one pot or shake and bake method.)
Rubber tubing
Dust or respiratory masks and filters
Funnels
Rubber gloves
Large plastic storage containers or tubs
Containers of multi-layered liquids
Coffee filters or other items including bed sheets, used as strainers and stained red
White powdery residue
Sheets or other coverings on windows
Gas cylinders or tanks that may contain anhydrous ammonia (especially if the gas cylinder has a blue top. A chemical reaction causes the brass valve to to turn blue when used to store the gas.)
http://www.ncdoj.gov/getdoc/72a0bdd...7d89bdc6/2-0-1-1-3-2-Signs-of-a-Meth-Lab.aspx
I had thought early on, that one of the nearby sheds or out buildings might have had a meth cooker going on. But I think LE would have stumbled upon the remnants of it, or smelled it, during the initial search.
Unless it was cleaned up and moved quickly. And the timeline seems short.