Mary Yeager and John Lithgow arrive to watch the Los Angeles Lakers game against the Denver Nuggets at the Staples Centre. Los Angeles, California - 21.05.09

The actor will play serial killer Walter Simmons, who is dubbed the 'Trinity Killer' because he always kills in threes, according to EW.com.

Lithgow's character moves to Miami, Florida - where Dexter is set - after avoiding capture for three decades.

Source: WENN