Earlier in his career, Crummey was a disc jockey at New York's WNBC and WAPP (where he briefly partnered on-air with Mark McEwen) in the 1980s, before moving to talk radio at stations such as KFI and KABC in Los Angeles, and KFYI in Phoenix.
He also substituted for Harry Smith and Mark McEwen on CBS This Morning, the predecessor to the Early Show, from 1997 to October 1999.
Mark Twain | Mark | Mark Wahlberg | Mark Knopfler | Mark Zuckerberg | Mark Rothko | Mark Antony | Mark the Evangelist | Gospel of Mark | Mark Ronson | Mark Spitz | Mark Foley | Mark Murphy (singer) | Mark Murphy | Mark McGwire | Mark Hamill | Deutsche Mark | Mark Taper Forum | Mark Millar | Mark Lewisohn | Mark Kermode | Mark Lanegan | Mark Waugh | Mark Rydell | Mark Goodson | Mark Owen | Mark Mothersbaugh | Mark Medoff | Mark Heard | Mark Dayton |
One of the few documentary videotape editors at "48 Hours" in NYC to become a producer, Twomey became a music producer for reporter Mark McEwen at CBS This Morning.