MASSAPEQUA PARK - Nassau County police say an officer who was killed in Massapequa Park was fatally shot by an MTA police officer well after other officers responded to a knife-wielding man barricading himself inside a home.

Forty-year-old Nassau County officer Geoffrey Breitkopf died at Nassau University Medical Center after being shot by MTA police officer Glenn Gentile.

In a statement, the Nassau County Police Department says detectives were responding to a report of a man wielding a knife near Front Street. After officers confronted Anthony DiGeronimo, 21, he fled and barricaded himself inside 5 Front St.

Police say DiGeronimo lunged at them with a knife after they entered the house and was shot and killed by officers. Nassau police say Breitkopf, who was assigned to the Bureau of Special Operations, was shot between eight to 13 minutes after DiGeronimo was killed by other officers.

Officials are now looking into what transpired causing the MTA police officer to shoot Breitkopf, who was in plain-clothes.

AP wire services were used in this report.