(HOUSTON) -- A massive manhunt in Texas stretched into its fifth day Tuesday for two armed robbers who gunned down in cold blood a mother of two described by a relative as a "light in a dark world" and had recently become engaged to be married.
Donna Pena, 31, was shot to death in a holdup at a Houston-area Shell gas station, according to the Harris County Sheriff's Office. Pena started working at the gas station three days before she was killed, her brother-in-law, Kevin Hamilton, told ABC News on Tuesday.
"Why? Just why? It was senseless," Hamilton said. "They have to pay."
the Harris County Sheriff's Office released surveillance video of the two gun-wielding robbers, both wearing bandannas over their faces, and one dressed in a hooded sweatshirt with the word "Navy" written on the front and back. His accomplice was wearing red sneakers with white stripes, police said.
Investigators said the fatal holdup occurred Friday night while Pena was working in the gas station's mini market, officials said.
In a horrific crime that took just 25 seconds, the two bandits bust through the front door about 10 p.m. with pistols in hand and mercilessly shot Pena dead before emptying the cash register, authorities said.
Sheriff's officials said the two men are believed to be responsible for five to 10 armed robberies in the Houston area, including one recently at a Subway restaurant.
"Getting these two men off the streets is a top priority for us. We owe it to Donna Pena, her loved ones and everybody that mourns her death, as well as the community that we are sworn to protect," Chief Deputy Edison Toquica of the Harris County Sheriff's Office said during a news conference.
Hamilton said Pena had previously worked for the chain of Shell gas stations in the Houston area, but quit to go to welding school. He said Pena went back to work three days before she was killed.
"She was actually just picking up a shift. That was not her regular store," Hamilton told ABC News.
He described his sister-in-law as "full of love" and is survived by a 4-year-old daughter and a 15-year-old son.
"She was there for everybody and she loved nature, she loved Texas and she loved just about everything," Hamilton said. "She was a light in a dark world."
Hamilton said Pena's boyfriend recently proposed marriage and she accepted.
He said Pena's son is distraught over his mother's death.
"He's trying to stay strong for everybody," Hamilton said. "It's just hitting her little girl. She thinks it's a dream and we're all going to wake up."
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