Emotions ran high at Bronx Supreme Court Monday as opening statements were delivered in the highly anticipated murder trial of Lesandro "Junio" Guzman-Feliz.

Family members and supporters of the Belmont teen who was fatally stabbed gathered at the courthouse for the proceedings. Five men are charged with first-degree murder in the case.

A spectator says Junior's father had to be removed from court after at least one of the defendants provoked the victim's family. Manny Ortiz, Junior's older brother, says it was defendant Manuel Rivera who cracked a smile.

MORE COVERAGE: Justice for Junior

Assistant District Attorney Morgan Dolan delivered the prosecution's opening statement to the jury of mostly women. She first painted Junior as a helpless boy who was brutally murdered with machetes and knives outside of a Belmont bodega last June by members of the Los Sures set of the Trinitarios gang.

Dolan told jurors that throughout the trial, they'll see evidence that the suspected killers came with a plan to kill someone they mistakenly believed to be a rival gang member.

Some defense lawyers for four of the defendants charged with first-degree murder appeared to place blame on Jonaiki Martinez Estreslla, claiming he was the only attacker who had the intent to kill. Police have said he gave Junior the lethal blow to his neck.

An attorney for defendant Jose Muniz says his client became the poster boy for the case because of the machete he was seen carrying, but claims he did not put a scratch on Junior.

But a witness called to the stand by the prosecutor appeared to counter that argument, saying she saw from a window a few men stabbing Junior multiple times.

The first witness recalled Junior's last words in front of the hospital before he collapsed and died: "I need water."

The prosecutors will continue to call witnesses to the stand Tuesday.