The entrance to the Anna Prayer Counseling and Retreat Center in Frederick County. A man who was staying there is accused of killing a missionary from South Korea on July 26 and wounding the man's wife. (Dan Morse/The Washington Post)

Authorities in Frederick have identified a man who was fatally stabbed, and his wife, who was badly wounded, in an attack at a religious retreat where they were serving as missionaries.

Chung Hwan Park, 62, was killed in the Sunday evening assault. His wife, Ae Suk Ko, 57, suffered serious wounds after she tried to defend him. They are both from South Korea and had been visiting the United States.

Song Su Kim, 30, of Falls Church, Va., was arrested and charged with first-degree murder and attempted first-degree murder in the attack on the couple at the Anna Prayer Counseling and Retreat Center in Frederick County. Kim, who is a U.S. citizen of Korean descent, told authorities that he had long felt disrespected by fellow Koreans and had hit a breaking point, according to court papers filed Monday.

Kim is being held without bail. He told investigators that he wanted to “invade a Korean” for the way all Koreans treated him, according to charging documents. He told authorities he had had those thoughts for eight years.

The couple, pastors from South Korea, were visiting the United States on a pilgrimage and were volunteering as cooks at the retreat, Frederick County Deputy State’s Attorney Nanci Hamm said. Authorities had declined to release the victims’ names Monday as they were working to notify family members through the South Korean Embassy.

Song Su Kim (Frederick County Sheriff's Office)

Authorities said that they think Kim, who had been staying at the retreat center for several days, got a knife from the kitchen Sunday before heading into a common area where others were waiting for him before an evening service was to begin. When Park asked Kim to sit down, Kim began stabbing him, according to court papers. Kim attacked Ko when she tried to help her husband, authorities said.

During a bond hearing Monday in a Frederick court, Hamm said Kim had previously been charged with assaulting a family member and destruction of property.

“This is really one of those crimes that’s hard to wrap your head around by way of motive or why something like this would happen,” Hamm said. “I think he is extremely dangerous.”

Defense attorney Elizabeth Steiner said Kim was homeless and previously had been staying at a homeless shelter in Fairfax County. She said he wasn’t working and was receiving Social Security benefits.

Frederick Sheriff Charles A. “Chuck” Jenkins said at a Monday news conference that Kim’s mother had brought him to the retreat center about five days ago. The sheriff said he did not know whether Kim had any other connection to the victims.

Kim’s family members could not be reached for comment Monday. Grant Chamberlain, a resident of the Baileys Crossroads Community Shelter, said Kim had been his roommate at the shelter for two months in 2013.

Chamberlain said Kim liked to listen to techno music and isolated himself from other residents. He said Kim told him his family lived locally and owned a business of some kind.

“He was really quiet and stayed up all night,” Chamberlain said. “He didn’t say a word to anybody.”

In the intervening years, Chamberlain said, he has seen Kim at another homeless shelter in Fort Belvoir.

Frederick sheriff’s officials said they first heard from Kim on Saturday when he called 911 and said he was “really unsatisfied with the food at the facility.”

“That was it,” Jenkins said. “There was nothing that indicated there were any problems there or with the individual.”

According to police reports and court documents, the attack at the center, several miles south of Frederick near Sugarloaf Mountain, unfolded as a few people preparing for a service were waiting for Kim to finish eating his dinner.

Kim, according to the witness, entered a common area with his hands behind his back, and when he was asked to sit down, he pulled out a knife and started stabbing the couple, the charging papers say.

The witness told investigators that she ran into the kitchen to call 911, and when she came back, Kim had fled, court papers say. Officials said they later found bloody footprints.

After the witness called for help, according to court papers, Kim placed a second 911 call.

In the call, Kim said he was on the road, on foot, “waiting to be arrested,” according to Jenkins. Court documents stated that Kim said he needed an ambulance because he had stabbed two people.

When asked whether he was okay, Kim answered: “Excuse me, sir? I just stabbed two people. I did it myself,” according to the court documents.

Park was found kneeling against a wall, authorities said. He was given medical attention but was pronounced dead at the scene.

Authorities said they later found that the man had suffered 11 deep stab wounds to his upper body. He had wounds on his back and defensive stab wounds to both of his forearms.

The man’s wife was “running around the building” when law enforcement arrived, according to court documents. She had suffered multiple severe stab wounds to her upper body. She was later flown to Maryland Shock Trauma Center in Baltimore.

“She’s conscious, she’s alert, she’s going to survive at this point,” Jenkins said Monday.

Authorities said arriving deputies found Kim on a road and took him into custody without incident.

Kim agreed to talk to detectives, according to court papers, and told them that the man he stabbed had treated him badly. He said he had wanted to kill a Korean and that the man had pushed him to his breaking point.

The witness later identified Kim as the person who stabbed the couple, according to authorities and court documents. Law enforcement officials said they spoke with Kim with the help of a Montgomery County police officer who speaks Korean.

The Anna Prayer Counseling and Retreat Center is off of a hilly, narrow road in a remote section of Frederick. A few informal signs — “Mt. Anna,” “Anna Prayer,” “Anna Prayer Counseling” — lead motorists to a one-lane bridge across Bennett Creek and into the center.

“It’s beautiful, absolutely beautiful,” said a 78-year-old woman, standing outside the entrance Monday evening. She said she has gone to the center for years. The woman, who lives in Harpers Ferry, W.Va., spoke on the condition of anonymity to protect her privacy. She and several other regulars said they did not have permission to allow strangers onto the land in the wake of the tragedy.

The woman said she had gotten to know the man who was fatally stabbed. “Very nice. Very dedicated. Very hardworking,” she said. She said it was heartbreaking that he and his wife were attacked. “They’re very good people.”

The woman said the center follows nondenominational Christianity rooted in the Bible. She said there are two chapels, and people worship, pray, study and fast there.

She said people at the center undoubtedly were trying to help Kim. “This is a prayer mountain. You try to help people through prayers,” she said.

Officials said Monday afternoon that they were looking for the weapon, which Kim said he dropped in an area of tall grass near the center, according to court papers.

Jennifer Jenkins, Justin Jouvenal, Victoria St. Martin and Martin Weil contributed to this report.