St. Louis County police say an off-duty officer has fatally shot a man who was trying to enter the officer's home.

Police say the officer, who wasn't identified, shot 20-year-old Tyler Gebhard after Gebhard threw a concrete planter through a window to enter the Lakeshire home Saturday evening.

According to police, Gebhard was known to the family and had recently made online threats toward it.

Police Chief Jon Belmar says the officer is on leave pending the investigation of the incident. He declined to elaborate on the nature of the threats.

An uncle of Gebhard, Patrick Brogan, told the St. Louis Post-Dispatch that Gebhard and the officer had been arguing on Facebook about Black Lives Matter. He said Gebhard, who was biracial, empathized with the group's objectives.