Cruz pleaded guilty last year over the killing of 14 students and three staff members at Marjory Stoneman Douglas High School in Parkland.
At least one of the 12 jury members did not believe the death penalty request, which was to be unanimous was warranted due to extenuating circumstances.
The jury's decision came on the second day of deliberations, bringing to an end a trial that began nearly six months ago.
#parklandtrial#NikolasCruz handed out 17 death sentences in one day. There were no trials or sentencing hearings. But a jury of peers couldn't hand out one death sentence after 3 months of testimony abt the brutality of his murder. Let's remember he also attacked a prison guard. pic.twitter.com/QINLHlMeae
Many family members of the victims were surprised, either shaking their heads or crying when the reading of the verdict on each of the 17 counts did not reflect the unanimity necessary to pass the death penalty.
Nikolas Cruz entered the first-year building of Marjory Stoneman Douglas High School (MSD) on February 14, 2018, with an assault rifle and opened fire indiscriminately.
This massacre sparked the largest demonstration in U.S. history in favor of greater gun control. A march on March 24, 2018, driven by survivors and victims' parents, brought together 1.5 million people across the country.
Even though this reignited the gun control debate in the United States, Congress has not passed any significant reforms.
A modest federal law was passed providing increased funding for school safety and mental health after the bloody shooting in May this year at an elementary school in Uvalde, Texas, that left 19 children and two adults dead.