HOUSTON – Authorities are asking for help after a woman was shot at point-blank range while setting up a garage sale in northwest Harris County.

Elizabeth Barraza, 29, was in the driveway of her home near Cedar Walk Drive and Princeton Place Drive, setting up a garage sale just before 7 a.m. when the shooting happened, authorities said.

A surveillance video showed a person get out of a black pickup truck, walk up to Barraza and exchange some words before shooting Barraza four times and fleeing the scene.

Investigators said the vehicle has been identified as a black, older model, four-door Nissan Frontier. While the vehicle has been identified, investigators said it is difficult to determine whether the person who shot Barraza was a man or a woman.

Barraza was taken to Memorial Hermann Hospital, where she later died.

Her husband, Sergio Barraza, said during a news conference that she died at the same hospital where the two had spent many hours volunteering and doing charity work.

“My wife, Liz, was a beautiful person … with the kindest of souls,” Sergio Barraza said. “Tragically, someone stole that away from us on the morning of Jan. 25. I’d just left for work that morning, and I’m just so happy that the last words I got to say to my beautiful wife were, ‘I love you’.”

VIDEO: Deputies give an update on garage sale shooting

During the conference, Barraza’s father said she had been setting up the garage sale in an effort to make a little more spending money ahead of her and her husband's fifth anniversary trip, which was scheduled for the Sunday after she was killed.

"We never imagined a life without her and we still can’t. We never will," Liz's father Bob Nuelle said.

Barraza’s loved ones are urging anyone with information about the case to come forward.

“I don’t understand how someone could do this to her,” Sergio Barraza said. “I had to trade our fifth anniversary for her funeral. We need justice for Liz. I need justice for Liz. I love you, Liz.”

According to investigators, they are still looking for a motive behind the killing and whether or not it was a targeted or random attack.

"I ask if anyone knows anything please come forward. Please come forward," Sergio Barraza said.

Neighbors heard the gunshots and dialed 911.

“It was three gunshots, real fast, one after the other. Waited a couple of seconds and then it was another gunshot,” Candy Ellis, a neighbor, said.

Crime Stoppers announced during the news conference that the reward for any information leading to the charging or arrest of Barraza’s killer had increased to $20,000.

The Harris County Sheriff’s Office has made no arrests in the case and is looking for leads.

"You have my word we’ll do everything possible to bring justice to Elizabeth’s killer," Sheriff Ed Gonzalez said.

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