The volunteer program is not open to just anyone. When people sign up to become a volunteer, the registration is not approved immediately. Only
after acceptance by the administrator someone can be alerted. Although
the administrator always has to accept every single volunteer who signed
up it is at forehand not clear for us whether a person has a criminal record as we do not have access to the public record of an individual.
However, in The Netherlands we perform sample testing to check whether volunteers have achieved the required training. An additional advantage of the alerting system is that several people are alerted at the same time, so that there are more volunteers present at the incident. This means that there is also a check at the incident. If desired, the volunteers may also be mandated to provide a certificate of good conduct when they sign up.