By MaryAnn Martinez

DUNCANVILLE (CBSDFW.COM) – She was the definition of a “sweet, old lady,” according to her family, but five years after she was gunned down in her home, no one has been arrested for the murder of Barbara Strain.

“We have no clue why this would be done to her — of all people,” said Morgan Poole, Strain’s granddaughter.

Photo of Barbara Strain. (credit: Texas Dept. of Public Safety)

The 74-year-old great grandmother died March 6, 2013 at her Duncanville home. Just after 7 a.m., she answered the door, talked to a stranger briefly, and shut the door. Then four bullets were fired from outside the house.

“I heard her yell when she was hit,” said Poole.

Right after the murder, the family handed out thousands of fliers, announcing a $15,000 reward for information. Duncanville police also released a sketch of a person of interest.

(credit: Duncanville Police)

It was a face Strain’s family didn’t recognize. After all of the family’s efforts, they’re still not any closer to knowing why.

“Not being able to sleep well at night because I don’t know who it is. I don’t know why they did it and I don’t know if they’re going to come after me or my kids,” said Poole.

Police have been working on this case for five years, ruling out several suspects, but they have yet to make any arrests. The family hired a private investigator in January, hoping some fresh eyes will finally lead to an arrest.

“I feel like somebody knows something and maybe they’re scared to say anything,” said Poole.

The $15,000 reward is still available. Anyone with information is asked to call Duncanville police.