A method apparatus are directed to identify items disposed on the bottom shelf of a shopping cart bottom of basket (BoB). Certain aspects envision a distance measurement sensor and computing system connected to the shopping cart. A first set of distance measurements of the bottom shelf when empty is obtained via the distance measurement sensor. Next, at a checkout stand, a second set of distance measurements of the shelf are taken, which can be used to compare with the first set of distance measurements to identify if there is an object on the BoB. An alert can be provided to a checkout attendant if there is an object on the BoB.