Veteran actor John Lithgow will join the cast of 'Dexter' in the upcoming fourth season.

According to EW, Lithgow will play "Walter Simmons, an unassuming suburbanite who has been living a dual life as one of America’s most prolific and deadliest serial killers."

Season 4 of 'Dexter' premieres September 27 on Showtime.

Click here for a great gallery of 'Dexter' photos

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