WILLIAMSON COUNTY, Texas (KXAN) — The family of a grandmother killed outside of Florence last week asked for the community’s help Thursday morning to find who shot her.

The Williamson County Sheriff’s Office said deputies found Diana Lynn Pier, 70, dead on the roadway about five miles south of Florence on Aug. 4. Deputies said a neighbor called 911 about a shooting in the 4500 block of County Road 245 around 8:45 p.m., which prompted them to check out the area.

“Our family now has a void that cannot be filled,” Marsha Garcia, Pier’s daughter, told reporters at a news conference Thursday. “We want the truth about what happened, and we want the person held accountable in a way that they cannot do this again.”

Deputies have made no arrests in this case yet. They said they’re searching for a light-colored sedan, possibly silver or gray, last seen in the area around the time of the shooting.

“We’re trying to talk to the suspect or suspects in this case. Personally, I don’t think that person has a soul or a heart because of this insane act of murdering a 70-year-old grandmother,” Commander John Foster, who leads the criminal investigation division, said Thursday.

The shooting happened after Pier drove home from meeting a relative in Round Rock, deputies said. They added they believe Pier may have stopped to help someone on the road before the shooting.

Foster said the sheriff’s office has six detectives dedicated solely to this homicide. He added deputies also asked for assistance with the investigation from the FBI and the Texas Department of Public Safety.

“This case is currently our top priority,” Foster said.

Pier’s husband and two daughters held up a photo of the smiling grandmother throughout the news conference. Deputies said there’s now a $30,000 reward being offered to anyone who can provide information that leads to the arrest and conviction of those responsible for Pier’s death. An “anonymous third party” put forward $25,000 of that amount, Foster said.

Anyone with details on what happened can call the Williamson County Sheriff’s Office at (512) 943-1311 or Williamson County Crime Stoppers at 1 (800) 253-7867.