'Dexter': John Lithgow makes a killing

Johnlithgow_30rock_290 John Lithgow is once, twice, three times the serial killer.

The Emmy-winning actor has signed on as the "Trinity Killer," Miami's latest bloodthirsty serial murderer for the fourth season of Showtime's "Dexter."

As Walter Simmons, Lithgow plays a seemingly mild-mannered suburbanite who enjoys using unique killing methods to take out his victims in threes -- hence the "trinity" label. Simmons has been tracked to Miami by the returning FBI Special Agent Frank Lundy (Keith Carradine), who two seasons ago had a relationship with Deb (Jennifer Carpenter) but had left to pursue a criminal in Oregon.

Naturally, Dexter (Michael C. Hall) gets all sorts of intrigued by the Trinity Killer, not the least for his innovative killing methods, but also for his ability to have carried out almost three decades' worth of murders without being nabbed.

Lithgow will be featured in all 12 episodes of the fourth season, which premieres on Sunday, Sept. 27.

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