Violent crime is rare in Costa Rica and remains mainly in the big city. However the increase in tourism has unfortunately also increased the incidence of theft. 

Be cautious in San Jose, use only metered taxis, always keep an eye on your luggage and avoid showing large amounts of money. 

Outside of the Big City and in Monteverde it is much safer, but the traveler still needs to be aware.

Remember if you are traveling by public bus your valuables are safe under the bus but use caution with your things in the cabin and always take them with you whenever you depart the bus.