On Friday at 10pm/9c, Keith Morrison tells the story of a couple who met over the craps table in Las Vegas. She was a beautiful trapeze artist and he was a professional poker player -- with a secret. Did he take a gamble that led to murder?

As part of our ongoing 20th season anniversary, we want to know, "How do you Dateline?"  Our own correspondents kick of the conversation by sharing how they each do Dateline.  Tell us how you Dateline on Facebook and Twitter: #HowDoYouDateline

In October 2009, James Arthur Ray, a renowned self-help author and speaker, held a "Spiritual Warrior" retreat in Sedona, AZ. Three people died during the retreat, and Ray was charged with manslaughter but convicted of a lesser charge. Chris Hansen reports Deadly Retreat this Friday, October 21st, at 9pm/8c.

Read the written statement that Chris Hall submitted for his sentencing hearing on July 22, 2011, as featured in the Dateline report Someone Was Watching from Sunday, February 24th, 2013: 

On June 7th, 2007, I lost my wife and my daughters lost their mother to a tragic accident. No matter how it is twisterd - 1/2 truths told or wild theories provided - the truth is it was a tragic accident that has devastated our family.

I loved Cristi on that day and I love her even more today.  Contrary to what has been told in this court there has never been any act of violence in our home let alone some "hidden rage of violence" as portrayed by the DA.

Cristi and I have 3 beautiful daughters that have grown up in a loving home to be smart, intelligent women.  As the girls were planning their adult lives, Cristi and I were looking forward to the rest of our lives together.  Cristi was my best friend and lover and I miss her terribly.

No matter how many high fives, back slaps, or congratulations that were provided on May 31st, 2011, it does not change the truth - and that I did not and never have hurt nor raised a hand to Cristi.

As much as I wish and know that I should not be here today being sentenced to a crime that did not even happen let alone I commit. There is nothing more you can do to me.  The worst day of my life has already happened on June 7, 2007.

Right now the only thing keeping me going is our 3 daughters Courtney, Briana, and Ashtin.  For if it was not for them and their future families I am not sure how I would feel about life at all.

Cristi and Chris Hall who were married for nearly 30 years and had three daughters, had what most people thought was the perfect marriage until Cristi was found dead in the backyard spa. Keith Morrison reports Someone Was Watching.

Dennis Murphy tells The Ballad of Mike & Dalia, and what was supposed to be a story-book marriage and new lease on life. Instead, lust, greed and deceit led to an elaborate murder plot that makes reality TV look like a fairytale.

Dateline NBC's Keith Morrison reports on a young woman's disappearance, following her chance encounter with a stranger on a train. Her desperate family hires a dream team of detectives to follow the mysterious trail she left behind. 

Strangers On A Train is an all-new Dateline report that airs Friday, October 7th, at 9pm/8c.