HOUSTON -

The search is on for the person responsible for a 57-year-old woman's death.

Sadie Butler died from a single gunshot wound on June 9. Her family is seeking justice. 

"We're asking you to have a heart. We were robbed of our mother. She was a grandmother, a daughter, an aunt, a friend. We just want some information," said Butler's daughter, Erica Boutte. 

A person driving in the 5600 block of Tidwell in northwest Houston found Butler's body at a bus stop, investigators said. That person drove to a nearby gas station and told the employee about the body. That employee called police. Now investigators would like to talk to the person who first made that discovery. 

"That person is not a suspect. We just want to know what he saw. He was driving a newer model dark blue or black Chevy Impala," Houston police Officer Mark Coleman said.

Butler's body was discovered at 6:15 a.m. She was known to walk in the area, but never that early. 

"At that time in the morning, we're really not sure why she would have left. We don't know exactly where she was going," said Boutte. 

Investigators said Butler's purse and cellphone were found at the scene, ruling out robbery as a motive. 

"We know at approximately 5:50 a.m. she called METRO, the automated number, to get information on the bus schedule. We don't know the type of information she was trying to obtain or what bus she was trying to ride. We know she did call them," said Officer Coleman.

Detectives said Butler was last seen alive leaving a relative's home about 4:30 a.m.

Anyone with information is asked to call Crime Stoppers at 713-222-TIPS.