Inspectors use XRF machines which use radiation to detect lead paint through multiple layers of paint without having to damage any surfaces. 

Just to clarify and respond to questions:I am working with my tenant (the one on the lease), her family, and am in contact with the detectives and other agencies helping her.  

You can use a photo editor to change the pics slightly (I do this too) and not be detected by any image recognition algo AirBNB may use.Require that a license holder reside in the primary residence XX number of days.

I got stung my dog got stung.. and its just a little hole in the ground in the shrubs so hard to detect until we saw them ingressing and egressing.. a professional had to take care of it.. don't know what it cost  .. 

The detectives revealed seizing a large amount of substance to be crack cocaine, ecstasy, cash, paraphenalia convicted felon in possession of a handgun, resisting arrest, tampering with physical evidence.

I can’t remember the ridiculous numbers exactly but it built a 16-17 story building in just a couple weeks or less.As a very forward preparing GC, we are getting ready and prepared to be sensor installers (plumbing pipes, wood rot detection, foundation shift, etc etc.).

After all, a rent roll is just a spreadsheet with names, dates, rental amount, and some other misc info; just a starting point for your detective work. 

Would a general contractor be able to detect this?

Secret service, witness protection, senator/house of rep, police detective, etc. 

I'm going to be a bit of a contrarian to the above posters, but let me first qualify my post by stating that your market will determine what you should do.We frequently install en-suite laundry in our units - in fact, we have removed common coin-op laundry in most buildings of 6-units or less in favour of en-suite laundry - for the following reasons:electricity and, in most cases, hot water costs are transferred to the tenant;where water is sub-metered, water costs are transferred to the tenant;high-efficency residential laundry machines are about half the capital costs of commercial coin-operated machines;we can command $30 - $50/month in additional rent with en-suite laundry;by installing our own machines, we know they are installed property, with catch/drain pans and {going forward} leak detect shutoffs; andwith en-suite laundry vandalism of laundry machines has been non-existant ... and if a machine is damaged, we know who is responsible.We have a good rapport with a couple of local appliance suppliers and get called whenever they have "dinged and scratched" units to unload ... a small, cosmetic dent in the side of a washer - which will never be seen when it is installed in a laundry closet - can be worth a 40 - 50% discount.