DALLAS (CBSDFW.COM) – There is yet another reminder in North Texas that domestic abuse is everybody’s business.

Just days after a Fort Worth man is arrested for the murder of his estranged girlfriend and the woman’s 10-year-old daughter, a Dallas mother is shot and killed at a Florida rest stop.

Investigators there say Jessica Ileen Quinones, 35, was trying to get away from her Dallas boyfriend after the relationship fell apart. Quinones died at the scene. Her 18-year-old daughter, Destiny Snider, was wounded.

After opening fire, police say 46-year-old Larry Donell Stuart turned his weapon on himself.

“They seemed like the perfect couple… seemed like a great couple together,” says Santos Vargas.

Vargas says he worked with Stuart for years and never knew him to be violent. He says the couple always appeared happy and spent lots of time together, playing baseball on a local team. Vargas says the news hit him and other coworkers hard.

“When I found out it was true, I had this pain like in my heart… like I still couldn’t believe it,” says Vargas. “But, it’s true. I still feel kinda weird in my heart.”

Vargas who worked with Stuart at a local apartment management company, says he spoke with him around noon on Monday, and he spoke ever so casually of why he wouldn’t be at work.

“He was on his way to do something important,” recalled Vargas, “something he had to go take care of.”

That “something” appears to have been a plan to follow or at least track his estranged girlfriend to Florida.

Investigators there say Quinones was leaving Stuart and was heading to her sister’s home in Melbourne when she was attacked. Witnesses told police that Stuart went from car to car at the rest stop until he found Quinones’ and then opened fire.

Her daughter, a senior at Dallas’ W.T. White High school, has undergone surgery at a Florida hospital and is expected to survive– and somehow manage life without her mother.

“I never thought Larry was capable of doing something like that,” says Vargas. “Never.”

Local experts say it is common for outsiders to be stunned in the aftermath of such violence because they may not have witnessed anything that raised an alarm– or perhaps those who knew the couple didn’t know where to look.

“There are always signs,” says Paige Flink, CEO of The Family Place, a local domestic abuse shelter. “Leaving is the most dangerous time for anyone in an abusive relationship. It’s important to always have a safety plan. Get help.”

“I can’t stop thinking that he did that,” says Vargas. “I just can’t. Hard to process something like that.”