Best known as the pencil-wielding team leader on the CBS hit drama “FBI,” Jeremy Sisto has steadily built an impressive acting resume thanks to a devotion to the sorts of details that bring his characters to life. Telly Savalas had his lollipops. Peter Falk had his trench coat. And Jeremy Sisto has his pencil.

Appearing on the hit CBS drama “FBI,” now in its second season, Sisto’s Assistant Special Agent in Charge Jubal Valentine commands an elite team of investigators in the Federal Bureau of Investigation’s New York field office, and he does it all while spinning, chewing and pointing a sharpened No. 2 as if it were an extension of himself.