Testing the top quark lifetime

Experiments at the Fermilab Tevatron are collecting large and exceptionally pure samples of top quarks, and performing measurements to confirm that the particle discovered in $p\bar{p}$ collisions a decade ago is the anticipated sixth quark. One unambiguous test is a measurement of the top quark lifetime, which is constrained by the consistency of the Standard Model to be less than $10^{-24}$ s. I will describe a search for anomalous decay lengths in $t\bar{t}$-like events observed with the Collider Detector at Fermilab (CDF), and report a first direct limit on the $t$ quark lifetime.