(CBS) NEW YORK -- "A parent should never outlive their child." There is almost a mathematical truth to the phrase. It's a saying that kept running through my head over the two days last February as I watched Deborah Edwards, mother of murder victim Dana Clair Edwards, testify in San Antonio during the murder trial of Thomas Ford.
After an emotional introduction of who exactly Dana Clair was - meticulously neat, animal lover, supportive daughter who moved home to help her father Darrell Edwards through prostate cancer -- the prosecution began to ask Deborah about the worst day of her life, January 2nd, 2009.
Mrs. Edwards described discovering Dana Clair's bloody and battered body on the floor of her condo in the ritzy San Antonio neighborhood of Alamo Heights. If losing a child is a parent's worst nightmare, then what Deborah and Darrell Edwards experienced in the early morning hours of that day, was that nightmare compounded by an unfathomable situation. She described finding her daughter's face covered in a bloody towel, the same towel which would become a pivotal piece of evidence later in the case, and removing it to see Dana Clair's beautiful green eyes one last time. If there was a dry eye in courtroom, I did not see it.
Mrs. Edwards then went on to describe how, as the murder investigation progressed and Thomas became the main suspect, she became frustrated that police had not yet made an arrest. Her reaction was unique, to say the least.
She began a letter writing campaign on Valentine's Day with a card sent to Thomas Ford that read "Valentine's Day, never the same." For the rest of 2009, Mrs. Edwards sent Thomas Ford dozens of notes, cards and even letters written from Dana Clair's own email account. One of those emails read "Why have you taken her from us... your worthless life will always be terror!" Another chilling note read: "There is always the first. The first cigarette before it becomes a habit, the first murder before it becomes thrillingly serial."
In the dozens of trials I have covered all over the country, I have never seen anything like it.
On a lengthy cross-examination, famed Texas defense attorney Dick DeGuerin painstakingly went over each and every message with Mrs. Edwards, characterizing them as a "campaign of harassment." Card after card was entered into evidence as Mrs. Edwards admitted, without shame, that she was the person who sent these messages to the man she instinctively believed was responsible for the murder of her only daughter. If DeGuerin's hope was to show the jury that the Edwards family was out to get Thomas Ford at any cost, it seems to have backfired. In a later interview jurors told us that they felt the cross-examination was gratuitous.
Instead, by handling the famous defense attorney with an composure and dignity in the face of tragedy, her testimony became a lesson in how grief can drive us to do things we might never think possible until you find yourself under the most horrific of circumstances.
This story was reported by CBS News' 48 Hours producer Chris O'Connell