Family members on Sunday mourned the deaths of a woman and her two children, slain a day earlier in what Herndon police called a “horrific” triple homicide the day before Father’s Day.

The woman was Claudia Menjivar, 34, and her two children, Dayana Gutierrez, 12, and Carlos Josué Gutierrez, 10, according to Erlinda Gutierrez, whose brother used to be in a relationship with Menjivar and is the father of the two children. The three died in their home in Herndon, police said.

“She was a good mom to my nephews. She was a hard-working girl,” Erlinda Gutierrez said. “She didn’t have any problems with anyone.”

Few new details emerged Sunday about the killings, but police said the deaths appear to be linked to a suicide that took place early Saturday at a parking garage in nearby Reston.

Fairfax County police responded just before 6 a.m. to a 911 call about “an emotionally disturbed person” at the parking garage in the 1900 block of Democracy Boulevard, according to Fairfax police spokesman Anthony Guglielmi. Officers arrived to find a man threatening to jump from the roof of the garage, which is at Reston Town Center.

Guglielmi said the man told police that people had been harmed inside a home in Herndon. Guglielmi said he does not know whether the man said he caused the harm.

The man jumped from the roof about 6:30 a.m., despite officers’ efforts to prevent it, and was pronounced dead at the scene, Guglielmi said. Fairfax police then contacted Herndon police and asked them to check on the house the man had mentioned in Herndon.

With assistance from neighbors, Herndon police entered the house in the 500 block of Florida Avenue, a neighborhood of single-family homes and apartments about a half-mile north of the Dulles Toll Road. They found a “very horrific” scene, Herndon Police Chief Maggie A. DeBoard said at a Saturday news conference. The three victims were found dead inside the home.

Police have not released the names of the victims or the man who died by suicide. DeBoard said investigators determined the man had “a personal relationship” with the adult victim. Guglielmi said the man told officers he was staying at the Herndon home.

Erlinda Gutierrez said police contacted her brother to inform him that his former partner was the woman who died Saturday, along with their children. Erlinda Gutierrez said her brother is not ready to speak publicly about the deaths.

She said she does not know much about how Menjivar died, except police told her brother a gun was involved. She said that she does not know the name of the man who died by suicide but that he was dating Menjivar. She said the man did not live with Menjivar.

Her brother and Menjivar separated almost a decade ago, Erlinda Gutierrez said. She said Menjivar is from El Salvador and worked as a housekeeper for Home2 Suites by Hilton. The children were enrolled at Herndon Elementary School, Erlinda Gutierrez said.

Menjivar loved music, Erlinda Gutierrez said, ranging from Mexican singer Chalino Sánchez’s 1990s song “Los Chismes” to contemporary Spanish-language music. Her biography on Facebook contains a lyric from La Makina’s “Nadie Se Muere”: “Nadie se muere por un amor que no le conviene,” which translates to, “Nobody dies for a love that does not suit them.”

Erlinda Gutierrez said she and her family are struggling to process the deaths. She said it has been especially hard for her parents, Dayana and Carlos Josué’s grandparents.

“I don’t know why someone would do that to two innocent kids,” Erlinda Gutierrez said.

Saturday, she said, was Dayana Gutierrez’s 12th birthday.