The 11 law enforcement officers weren't looking for Christina Korbe when they showed up outside the sand-colored brick house on Woods Run Road just before 6 a.m. yesterday.

But she was there, armed with a .38-caliber handgun, and moments later FBI Agent Samuel Hicks -- the first in the door behind a battering ram -- lay dying. Last night she was charged with homicide in his death.

The agents and officers had a warrant for Robert Ralph Korbe, Ms. Korbe's husband, when they arrived at the Korbe home in Indiana Township. They knew that he had skirmished with officers in the past -- and even once dislocated an officer's shoulder. But he wasn't considered to be the most dangerous of the 35 people they were seeking in a drug round-up yesterday.

According to a police affidavit, the officers knocked on the door and ordered Mr. Korbe, 39, to give himself up. When he refused,officers burst through the front door.

Ms. Korbe, who was upstairs with her 10-year-old daughter and 4-year-old son, didn't know what was happening, her attorney said last night. She later told police she retrieved a gun from a bedroom closet and fired a single shot down the stairway.

She said she never heard officers identify themselves as police.

The bullet hit Agent Hicks in the left collarbone above his bulletproof vest.

"I'm hit," Agent Hicks shouted, and fell to the ground. He was wounded so severely that his fellow officers thought he'd been shot in the head. He was pronounced dead at UPMC St. Margaret at 6:52 a.m.

Agent Hicks, 33, was the first FBI agent to be killed in the line of duty in the Pittsburgh region. The last FBI agent killed in the line of duty was Barry Lee Bush, 52, who was accidentally shot and killed by a fellow agent as they pursued three armed bank robbers on April 5, 2007, in Readington, N.J.

Michael A. Rodriguez, special agent in charge of the Pittsburgh FBI office, said Agent Hicks joined the FBI in March 2007 and was assigned to Pittsburgh in August 2007. He lived in Richland and is survived by a wife and 3-year-old son.

"He served with honor and bravery and will be greatly missed by his colleagues here in Pittsburgh and throughout the FBI," a visibly heartsick Agent Rodriguez said in brief remarks, flanked by officials from the FBI, DEA and Allegheny County police.

County police last night charged Ms. Korbe with firing the shot that killed Agent Hicks after holding her through the day at their headquarters in Point Breeze. Shortly before 7 p.m., she was taken away in an ambulance after complaining of stomach pains and was expected to be arraigned today.

Her attorney, Sumner Parker, said she believed intruders had broken into her home and, concerned for the safety of her two children, fired at them. She called 911 at 6:05 a.m. to report a burglary and shooting.

"This was what appears to have been a very chaotic and stressful situation," Mr. Parker said. "She may have taken a course of action she believed was appropriate to her, which is not to attempt to mitigate the circumstance that the agent was killed.

"She was in a house where she had two young children she was responsible for."

But police said the Korbes knew who was at their door when law enforcement officers arrived. A police affidavit said officers knocked at the front door and when Mr. Korbe asked who was there, officers identified themselves.

"They definitely knew the police were outside," said a law enforcement official familiar with the raid. "They were talking to the guy through the door, telling him to give himself up. He refused."

Mr. Korbe later stated that when he realized police were at his front door, he fled to the basement where he was keeping some cocaine and poured it down a washtub drain. He went out a back door where he was quickly arrested.

The agents were in gear, wearing bullet-proof vests, while executing their part of a 200-officer operation executing simultaneous raids around the county. Led by the federal Drug Enforcement Administration, the FBI and city police, the raids targeted a large drug-distribution ring operating primarily in Brookline, Allentown, Beltzhoover and Mount Washington.

An indictment returned Nov. 12 includes a total of 27 counts against 35 defendants.

Mr. Korbe is charged in three of those, including conspiracy to distribute five kilograms or more of cocaine and 50 grams or more of crack; and two counts of possession with intent to distribute cocaine.

The charges against Mr. Korbe include possession of cocaine on May 24 and July 9. Assistant U.S. Attorney Troy Rivettisaid Mr. Korbe's previous drug convictions could mean life in prison if he is convicted on the new counts.

Mr. Korbe was the last of the defendants to appear yesterday before U.S. District Magistrate Judge Lisa Pupo Lenihan, who ordered that Mr. Korbe be detained until a formal hearing Monday. He made no statement when he was led from the courtroom, although he'd earlier told waiting reporters outside county police headquarters, "They shot their own guy."

Investigators quickly issued a denial.

Ms. Korbe, a stay-at-home mother, met her husband at Fox Chapel Area High School and married him in 2004. She had no criminal history save for a speeding ticket she received in September from Shaler police.

Mr. Parker said the Korbe children are staying with Christina Korbe's parents.

Court records show Mr. Korbe has a lengthy criminal record stretching back 17 years.

Most recently, in August, he was ordered to stand trial on charges of aggravated assault, reckless endangerment, criminal mischief, resisting arrest, escape, disorderly conduct, and possession and possession with intent to deliver cocaine.

The charges were filed by Sharpsburg police in connection with an incident in May in which Mr. Korbe fought with officers from several departments and seriously injured the shoulder of an Etna officer, who remains off duty.

Mr. Korbe, who runs Deluxe Car Care and D&J Variety Store on Main Street in Sharpsburg, had been free on $25,000 bond. He was to be formally arraigned today on those charges.

Yesterday afternoon, police raided the variety store and seized several machines and illegal gambling equipment.