  We report results of a search for Weakly Interacting Massive Particles
(WIMPS) with the silicon detectors of the CDMS II experiment. This blind
analysis of 140.2 kg-days of data taken between July 2007 and September 2008
revealed three WIMP-candidate events with a surface-event background estimate
of 0.41^{+0.20}_{-0.08}(stat.)^{+0.28}_{-0.24}(syst.). Other known backgrounds
from neutrons and 206Pb are limited to < 0.13 and <0.08 events at the 90%
confidence level, respectively. The exposure of this analysis is equivalent to
23.4 kg-days for a recoil energy range of 7-100 keV for a WIMP of mass 10
GeV/c2. The probability that the known backgrounds would produce three or more
events in the signal region is 5.4%. A profile likelihood ratio test of the
three events that includes the measured recoil energies gives a 0.19%
probability for the known-background-only hypothesis when tested against the
alternative WIMP+background hypothesis. The highest likelihood occurs for a
WIMP mass of 8.6 GeV/c2 and WIMP-nucleon cross section of 1.9e-41 cm2.
