Apparatus and methods are disclosed for verifying identity using a plurality of biometric samples collected during a pre-enrollment phase, where the plurality of biometric samples concern one or more biometric measures. In one embodiment, the biometric measure comprises an individual's signature, samples of which are collected over a period of time prior to an enrollment procedure. Collecting signatures over a period of time prior to an enrollment procedure allows a more robust signature model to be developed since the signature model will reflect natural, statistically significant, variations that occur over time. During an enrollment procedure, the user then attests to the validity of the signatures collected during the pre-enrollment phase. Valid signatures are used to construct a signature model that will be used to authenticate signatures provided during later transactions. Apparatus and methods of the invention additionally encompass collecting biometric samples of other biometric measures such as, for example, facial appearance, during a pre-enrollment phase.