The killers used two guns and fired over 40 shots in an ambush that also seemed personal.
"We had that aspect of, this is somebody they knew or trusted," explained crime scene investigator Andrew Taravella.
The victims' families and friends mourned the deaths of four recent high school graduates. The dead were 18-year-olds Rachael Koloroutis and Tiffany Rowell; Tiffany's boyfriend, 19-year-old Marcus Precella; and Marcus' cousin 21-year-old Adelbert Sanchez.
The community was left unsettled. Who could have done such a horrible thing?
Hundreds of tips to Houston police went nowhere, and for three years the multiple murders went unsolved, until one of the suspects, Christine Paolilla, talked a little too much.
"We always tell our kids the boogeyman doesn't exist. Monsters are make believe. They don't exist. Well, that's not true," prosecutor Rob Freyer said. "Because they do exist. Christine Paolilla is a monster. She quarterbacked this entire tragedy. These were her friends."
In the latest ABC13 Texas True Crime episode, Jessica Willey takes you inside the investigation and interrogations, and details how police were eventually able to solve the crimes.
It took three years, but Paolilla, once "Miss Irresistible" to her classmates, would instead become known as a murderer.
Watch Texas True Crime: Miss Irresistible wherever you stream ABC13.
Watch Texas True Crime on your favorite streaming devices, like Roku, FireTV, AppleTV and GoogleTV. Just search "ABC13 Houston."
MORE TEXAS TRUE CRIME: All American Killers
Texas True Crime: All American Killer