What are the signs that a Crystal Meth lab may be present?

The following, often in combination with each other, may indicate the presence of a Crystal Meth lab:

Curtains always drawn, windows covered with aluminum foil or "blacked" on private residences, garages, sheds, or other structures

Evidence of chemical waste or dumping

Excessive amounts of trash, particularly chemical, coffee filters or pieces of cloth that are stained red, and duct tape rolls

Extensive security measures or attempts to ensure privacy (no trespassing or beware of dog signs, fences, large trees or shrubs)

Frequent visitors, particularly at unusual times

Secretive or unfriendly occupants

Unusual odors (ether, ammonia, acetone, or other chemicals)