Gregory Vernon Patterson, a third man charged in a plot to attack Southern California military sites and other targets, has pleaded guilty to a terrorism conspiracy charge.
Two other men charged in the plot pleaded guilty last week.
Winston Kevin McKesson, an attorney for Patterson, says his client entered the plea Monday in federal court in Santa Ana.
Patterson, 23, faces penalties ranging from five years to life in prison when he is sentenced on April 14.
Authorities say Patterson was linked to a California prison gang cell of radical Muslims that planned attacks in the Los Angeles area.
Police uncovered the plot in July 2005 while investigating a string of gas station robberies that authorities say were committed to finance the operation.