"Water."

That was the last word 15-year-old Lesandro "Junior" Guzman-Feliz spoke when he was savagely killed with a machete in a Bronx bodega last summer, a killing that rocked the city -- and the nation -- for its caught-on-camera brutality.

The first witness took the stand Monday after lengthy opening statements from the prosecution and defense attorneys for five suspected gang members, the first of 14 to stand trial. The witness said she watched the attack from an apartment window and ran downstairs to try to help. She described, in heartbreaking detail, how Guzman-Feliz looked up at her after the attack and motioned her to call 911.

He only said that one word -- "water," she testified. She will resume her testimony on Tuesday. 

In opening statements, prosecutors described the teen's killing as a calculated and planned murder by the five suspects. Five defense attorneys also spoke Monday, four of whom described most of Guzman-Feliz's wounds as superficial and said it was the one cut to the throat that killed him. The defense attorney for the man who allegedly dealt that throat cut took offense at that.

Jury selection proceedings started last month for the suspects facing murder charges in the June 2018 attack on Guzman-Feliz, who prosecutors have said was cut down at just 15 years old in an apparent case of mistaken identity.

Investigators say the group mistook Guzman-Feliz, who was not affiliated with any gang, for a member of the rival fraction of the Trinitarios gang. In total, more than a dozen suspects have been arrested in connection to the killing. Nine others charged in the killing are awaiting trial.

The attack on Guzman-Feliz was captured on video; he was dragged outside the bodega and set upon by a gang of men who hacked at him as he struggled to defend himself. The boy was slashed in the neck and died after running to a hospital three blocks away.

Guzman-Feliz had been part of the NYPD's Explorers program, a group for youths interested in a law enforcement career. The New York City Police Foundation announced it planned to set up a scholarship in his name.

Since the violent attack, the community’s outpouring of love and support has been seen in a mural. Guzman-Feliz’s memory has also been honored through  the renaming of a street and a summer camp at a state park, as well as prompting the “Safe Haven Bodega” program in the city.