DUNCANVILLE (CBSDFW.COM) – The reward for information leading to an arrest or indictment in the murder of Barbara Strain, 74, has increased to $15,000.

Friends and family members of the woman affectionately known as “Granny” spent most of Saturday putting up and passing out more than 7,000 fliers, hoping someone will come forward with information on the suspect.

Duncanville Police say someone knocked on Strain’s front door Wednesday morning around 7:30 a.m. When she closed the door, the gunman fired several shots through the door, killing Strain.

MORE: 74-Year-Old Woman Shot After Answering Front Door

Bryan Strain, 26, Barbara Strain’s grandson, was in the home when the shooting took place.

“I hadn’t even rolled out of bed yet and I just heard 4 shots,” he said. “I ran into the living room. My grandmother was laying on the floor. It happened in front of my son and 2 nephews.”

The children were getting ready to go to school.

Three days after her murder, the killer remains on the loose. Duncanville police released a vague description of the suspect and have few clues about a motive.

“She was the definition of a sweet old lady,” Bryan Strain said. “She took in three of my friends when I was in high school at different times. Our home was anybody’s home. She never turned anybody away for anything.”

Bryan Strain and his sister and their respective children lived with their grandmother and had a very close relationship.

Bryan Strain says his family is devastated and the only way they’ll find closure is to find the man who killed the woman they loved so much.

“We don’t want people to forget. We need this to stay fresh in people’s minds so my grandmother can get some justice,” he said.

Oak Farms Dairy offered a $10,000 reward and Crime Stoppers has offered a $5,000 reward for information in this case.

Contact Crimestoppers at 1-877-373-TIPS (8477.)

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