An arrest has been made in the fatal stabbing of a Mastic teen.

Police say 19-year-old Michael Dennis fatally stabbed 17-year-old Trevor Bender on Mastic Road Friday night.

They say Bender was stabbed in the chest after he got into an argument with a group of acquaintances.

It's unclear what sparked the argument.

Dennis is expected to be arraigned on manslaughter charges.