Yusef Staine was shot and killed in February of 2022 by a man he was traveling with, according to police.
20-year-old shot and killed on LIRR train
It happened on a Penn Station bound train on the Ronkonkoma line.
On Thursday, Suffolk County Police arrested 20-year-old Yonkers resident Nicholas D'Agostino.
He has been charged with second degree murder and will appear in court on Friday.
Police said that all along they believed the killer and victim knew each other.
RELATED: Eyewitness News is tracking crime and safety across New York City and in your neighborhood
There's no word yet on a motive.
----------
* Get Eyewitness News Delivered
* Follow us on YouTube
* More local news
* Send us a news tip
* Download the abc7NY app for breaking news alerts