A sheriff’s office mobile command unit is seen in the parking lot outside the entrance to the Costco in Sterling on Wednesday. (Caitlin Gibson/The Washington Post)

As authorities continued to investigate Wednesday’s fatal shooting of a woman by a Loudoun County sheriff’s deputy, the Philippine Embassy on Thursday called on officials to take an aggressive look at whether deadly force was needed.

At the busy Costco store in Sterling, deputies had encountered 38-year-old Mhai Scott, who was armed with a knife and possibly a pair of scissors, according to sheriff’s officials.

Authorities said that Scott did not respond to commands to drop the knife and that one of the deputies used a Taser to try to subdue her as she moved toward them. Scott continued to advance, officials said, and a deputy opened fire, striking and killing her. A second deputy was hit by a bullet in the leg and is recovering.

Scott, a Filipina, lived in Loudoun and worked serving food at the store. In a prepared statement Thursday, Philippine Ambassador Jose Cuisia said the embassy shares “concerns expressed by Ms. Scott’s family in the Philippines and the members of the Filipino-American Community that law enforcement officials may have responded with disproportionate force.”

The statement continued:“We request authorities to conduct a thorough, impartial and expeditious investigation of the incident.”

Loudoun County Sheriff Michael Chapman said Thursday that a “thorough investigation” was underway and that Virginia State Police were involved. He had previously said he had confidence in the way deputies responded.

“When you look at the situation, somebody advancing on you with a weapon . . . she kept on coming, and she was coming in a threatening way,” he said Thursday. “Nobody ever wants this to happen. It’s tragic. You never want it to end this way.”

Chapman said the two deputies involved in the incident, who have not been identified, were experienced. Both have been placed on paid administrative leave, a routine step in such instances.

“These deputies are not rookies,” he said. “Both have several years on the job, and both are fully certified and have maintained all their training.”

Scott, who lived in an apartment near the Dulles Town Center, worked for Club Demonstration Services, which provides services to Costco, authorities said. A co-worker said Wednesday that police were called after Scott, who had been serving pizza during her work shift, suddenly became agitated and began behaving erratically.

In an interview aired on ABS-CBN News, a television network in Manila, Scott’s mother, Medina De Leon, and a sister, Melody De Guzman, expressed sorrow and anger over Scott’s death. Both spoke in Tagalog, their native language.

“Why did they do that? My daughter did not kill or hurt anyone. The killing was brutal,” De Leon said through tears.

De Leon said in the interview that Scott had been depressed because she was involved in a dispute with her ex-husband over custody of their two daughters.De Guzman said she had spoken to her sister just an hour before she died.

De Leon and De Guzman said they would ask the Philippine Department of Foreign Affairs and the Philippine Embassy in Washington to look into Scott’s death.

Scott’s ex-husband declined to comment Thursday.

Officials at the Migrant Heritage Commission, a nonprofit organization that offers social and legal services to immigrants, said they were attempting to contact Scott’s family to offer free legal services. Spokesman Arnedo Valera said the commission was concerned about the use of deadly force and would seek information about the training provided to the deputies who went to the scene.

Elmer Cato, a spokesman for the Philippine Embassy, said that Scott’s mother and sister live north of Manila and that she has an uncle who lives in the Washington area.

William Branigin, Ian Shapira, Raquel Edora, Magda Jean-Louis and Jennifer Jenkins contributed to this report.