Incarcerated former CIA worker Harold J. Nicholson (seen here) pleaded guilty Monday to conspiring to act as an agent of Russia. His son, Nathaniel, pleaded guilty last year to conspiracy charges in connection with the elder Nicholson's spy activities. (Associated Press)

Incarcerated former CIA worker Harold J. Nicholson (seen here) pleaded guilty Monday to conspiring to act as an agent of Russia. His son, Nathaniel, pleaded guilty last year to conspiracy charges in connection with the elder Nicholson's spy activities. (Associated Press)