Grandmother gunned down answering the door at her Texas home. But, DNA might help police solve her case.

Marianna Wilkinson was with her husband and watching the Dallas Cowboys beat the Detroit Lions on Dec. 9, 2007. Around 8 p.m., the doorbell rang and Wilkinson went to answer it.

That is when a suspect opened fire, shooting Wilkinson at least three times.

She was killed, and now her homicide investigation has gone cold. But, in 2019, police got a bit of a break in the case that they are still hopeful to solve.

Wilkinson was born on Nov. 4, 1939, and was a mother to two children and grandmother to four, according to the Texas Department of Public Safety. She graduated from Sothern Methodist University in 1961.

She was also active with her church, First Baptist Church, of Keller, Texas and attended a bi-weekly prayer group, according to police. Wilkinson was married to her husband for 46-years and the two enjoyed their retirement years by traveling.

On the night of her murder, Wilkinson was in her North Richland Hills, Texas, home when she was gunned down.

"My wife has just been shot," her husband Don told 911 dispatchers, according to WFAA. "Somebody rang the doorbell and then shot her. I need some help quick."

Police said they do not believe the shots were meant for Wilkinson as she had no enemies.

Her son, Mike, told WFAA that he hasn’t forgotten the night and its especially prominent around the holidays.

"You always live with it, and it changes you forever," Mike he told WFAA. "You know there's no rationality for going to someone's door and shooting them no matter who they are."

The gun used in the shooting was recovered and a partial fingerprint has been found, according to WFAA. In 2019, a DNA profile was created of a possible suspect, but no arrests have been made.

"We're very grateful and very hopeful that it will turn into something," Mike said.

A $3,000 reward is being offered in the case and anyone with information is asked to contact (800) 252-8477.