by either the prosecutor or her police officer husband, authorities said.
The shooting, shortly before midnight Monday, comes two weeks after Colorado's prisons director was slain as he answered the front door to his home, and two days after the district attorney of Kaufman County in Texas was found shot to death with his wife.
An assistant prosecutor in the Kaufman County district attorney's office was shot to death on January 31, and authorities have said both Texas murders and the March 19 slaying of Colorado prisons chief Tom Clements appeared to be targeted killings rather than random acts of violence.
"There are no apparent ties to recent shootings; however, investigators continue to pursue all possible leads and background information on this (dead) person," the bureau said in a written statement.
Authorities did not immediately release the names of the deputy prosecutor and her husband in connection with Monday night's shooting.
The deputy district attorney made a 911 emergency call and reported that a man was at her door "behaving very erratically," police said.
The prosecutor then told dispatchers that the stranger forced his way into her home. An altercation ensued inside and shots were fired, leaving the unidentified man dead, police said.
A spokeswoman for one of the agencies investigating the incident told Reuters that the prosecutor and her husband, himself a sheriff's deputy, both fired at the intruder, but it is too early in the probe to know who fired the fatal shot.
Authorities have matched the handgun used in Clements' slaying to the weapon used by a recent Colorado parolee, 28-year-old Evan Spencer Ebel, in a gun battle with police following a high-speed chase through Decatur, Texas, last month.
Investigators have named Ebel, a member of a white supremacist prison gang, as a suspect in the killing of Clements and in the death of pizza delivery man Nathan Leon, 27, who was found dead in suburban Denver two days earlier.