Investigators are looking for evidence in the alley next to the restaurant where a fight broke out friday night.
Witnesses say there were about 50 people outside when a brawl broke out and 27- year old Anatonio Lacertosa was stabbed.
Staten Island native John Perrotta says he saw a vicious sight erupt inside an Annadale restaurant bar and pour into the streets.
It's where police say Lacertosa was stabbed in the chest with a knife.
Blood stained yellow tape marks the spot.
Witnesses say Lacertosa was celebrating his engagement with family and friends when the fight broke out.
During the fight, a restaurant worker grabbed a knife and stabbed Lacertosa, then fled the scene.Lacertosa was rushed to Staten Island University Hospital where he died.
Jamie Caruvana was Tony's brother in law.
Sunday night on the front step of the family home, he tried to convey to us how much this Staten Island family has lost.
"He was the glue," said Caruvana. "He was the glue for this family. He took this family on his back."
The night began with a young couple so full of life, so optimistic about the future. Tony and his fiance Bridgette celebrated what they hoped would be a lifetime together.
A moment of anger and rage...suddenly turned some many lives upside down.
"it's hard for me, I can't imagine how hard it is for her," said Caruvana. "i'm just so honored to have known for him for the last 16 years that I knew him".
Get Eyewitness News Delivered