>> reporter: hired to move cash from stores to secret vaults. >> we don't like to say how much our clients have in their store. >> reporter: pot advocates who argue weed is less harmful than alcohol point out that overall crime is down. though any connection to marijuana is hazy. >> the system of regulation is actually safer for the public than an unregulated black market. >> reporter: they have been closely watching in washington state where recreational stores open this week. >> there you go. >> thank you. >> reporter: hoping to avoid the growing pains felt in colorado. ganja's ground zero. clayton sandell, abc news. >> we do like to kid about this, but of course you're impaired when you're high. there was one death linked to edible marijuana, a college student lept to his death from a hotel balcony. >> approved in 2012 by voters to