George Hitcho Jr., 46, is accused of killing Officer Robert Lasso of Freemansburg in Northampton County.
He appeared in court for a preliminary hearing on Monday.
Lasso was shot and killed on August 11th when he responded to a domestic disturbance call at Hitcho's home.
In court, Chief George Bruneo said he was called to the scene as backup and arrived to find Officer Lasso warding off two of Hitcho's dogs - a German shepherd and pit bull.
Lasso was trying to hit the dogs with a Taser, Bruneo said, when a shotgun blast erupted and Lasso fell to the ground.
Hitcho was arrested at the scene without further resistance.
"There's going to be, probably, a defense that this defendant believed - irrationally - that his dogs and or his property or himself was in danger of harm, and that resulted in the shooting," said Northampton County D.A. John Morganelli.
Trooper Dennis Sims told the court that Hitcho said, while in custody, "He ain't coming on my property without a warrant. He tried to kill my dogs and pointed a gun in my face."
Morganlli said he is seeking the death penalty.
"There is an aggravating circumstance present because, being a law enforcement officer killed in the line of duty, makes it a capital case," Morganelli said.
Hitcho was represented by a public defender who did not comment after the hearing.
Hitcho is being held without bail on homicide and other charges.