The Ladykillers (2004)

Goldthwait Higginson Dorr III is a charlatan professor who has assembled a gang of experts for the heist of the century. The thieves are experts in explosions, tunneling and muscle. The professor is their critical inside man. The base of operations is the root cellar of an unsuspecting, church-going, little old lady named Mrs. Munson. The ruse: the five need a place to practice their church music. The problem: it quickly becomes evident that Dorr's thieves lack the mental capacity to do the job. The bigger problem: they have seriously underestimated their upstairs host. When Mrs. Munson stumbles onto their plot and threatens to notify the authorities, the felonious five decide to 'do her in' before she ruins their heist. After all, how hard can it be to knock off an old lady? They'll soon find out.