GRAPHIC: Teen stabbed to death as dozens watched, videoed his final moments; arrest made

NASSAU COUNTY, N.Y. (WCBS/WPIX/CNN) - A man suspected in the fatal stabbing of a 16-year-old that was recorded and live-streamed by onlookers pleaded not guilty to murder charges in court Thursday.

Tyler Flach, 18, was ordered by the judge to be held without bail. He faces a second-degree murder charge in connection to a fight that turned deadly in a strip mall parking lot.

Police say some of the final moments of 16-year-old Khaseen Morris’ life were recorded on phones and streamed on social media.

"They videoed his death instead of helping him," said Lt. Stephen Fitzpatrick, a Nassau County homicide detective. "Kids stood here and didn't help Khaseen. They would rather video this event."

Police say dozens of people watched an unarmed Morris get stabbed Monday and did nothing to help.

"There's got to be about 50, 60, 70 kids here. We have a handful of kids that have come forward that have identified subjects involved in this. There is definitely more," Fitzpatrick said.

Morris was taken to a hospital, where he later died. Investigators said the fight Morris was involved in was over a girl.

"It's over a common girl and the perception of who she might be dating or who she might be hanging with," Fitzpatrick explained.

Homicide detectives are now urging - and warning - witnesses to come forward.

"You need to get out in front of this,” Fitzpatrick stressed. “After I put handcuffs on you is not going to be the time to be helpful for you."

Officials said police presence has now been beefed up around the school and the area where the fight took place.

"You guys took my brother away from me and my family," said Keyanna Morris, the victim’s sister.

At least one person has been arrested and charged with Morris’ death. That suspect is expected to be arraigned Thursday.

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