A teen fatally shot his ex-girlfriend dead inside his Long Island home before turning the gun on himself — and surviving, according to authorities.

The unidentified 17-year-old gunned down his ex-girlfriend, Emily Finn, 18, inside his home in Nesconset around 11:10 a.m. on Wednesday, the Suffolk County Police Department said in a statement.

An unidentified 17-year-old fatally shot his ex-girlfriend, Emily Finn, 18, inside his Nesconset home before turning the gun on himself. James Messerschmidt

The teen then shot himself in the face, cops said.

His parents called 911 after the shots rang out, according to police.

Finn was tragically pronounced dead on the scene, police said.

Finn was pronounced dead on the scene, and the 17-year-old was taken to the hospital in critical but stable c

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