D'Zondria Wallace dreamed of building a new life for her family in Minnesota. She never got the chance.

Less than six months after she had relocated to St. Paul, a gunman fatally shot Wallace and her two children inside their Payne-Phalen apartment. Police are investigating the slaying as a possible act of domestic violence and arrested a 26-year-old person of interest Sunday night.

"I can't stop crying. My babies are gone," her mother, Mary Wallace, said in a phone interview from her home in Memphis before the arrest was made. "I need justice."

In a scene that Chief Todd Axtell described as "hellish," first responders on Saturday found Wallace, 30, and her 14-year-old daughter, La'Porsha, dead inside the fourplex in the 700 block of Jessie Street. Her son, Ja'Corbie, 11, died a few hours later at Regions Hospital. Wallace was two months pregnant.

An officer had been called to the home on a welfare check only an hour before the shooting. He turned away after D'Zondria answered the door and assured him that she was all right.

The killing occurred just two blocks from the scene of a double homicide on Jan. 21 and shook a capital city already plagued by levels of gun violence not seen since the mid-90s.

Wallace, affectionately known as "Tweety" to those closest to her, had recently lost her housing in Greenwood, Miss. Wanting more stability for the children, she asked her first cousin to take them in until she could make the move north.

Jeanette Whitehall drove them back to her White Bear Lake home in the summer of 2019, where she enrolled them in school and extracurricular activities alongside her own children.

"They were really excited, especially for the snow," said Whitehall. "I treated those kids like my own."

They stayed for more than a year. La'Porsha played basketball for Roseville Area Middle School and was prepping hard for high school tryouts next year.

She aspired to one day be drafted in the WNBA. Ja'Corbie, an energetic kid with a big smile, attended Central Park Elementary in Roseville and loved video games, especially Fortnite.

Things had begun to settle into place by fall of 2020: Wallace found an apartment where the family could reunite and started a job as a personal care attendant.

But the three lived there only a few months before tragedy struck.

On Saturday around 3 p.m., neighbors on Jessie Street were jostled by gunfire.

A nearby resident reported hearing nine to 10 pops — in three separate spurts — before seeing several people running from the house.

Police were met out front by the 911 caller, who said people were injured inside, said department spokesman Sgt. Mike Ernster.

The 911 caller, later identified as Wallace's uncle, found the door slightly ajar. Behind it, La'Porsha lay mortally wounded. Wallace was found dead on the couch, according to emergency dispatch audio.

En route to the hospital, paramedics relayed that Ja'Corbie lacked vital signs after suffering gunshot wounds to the chest and arm. A chain of frantic phone calls sent Whitehall rushing to the scene, and then the hospital, awaiting news about his condition.

Eventually, a surgeon emerged with grim news, saying, "Ja'Corbie fought as hard as he could."

It came as a devastating blow to family already enveloped in grief. "It's sad we weren't there to protect them," Whitehall said.

During a press briefing on Saturday night, Ernster said, "Every homicide is hard, but this is especially a tough one." He noted that the officer was sent to the home earlier that night by an out-of-state relative who wanted a welfare check on a female in the residence. It was not immediately clear which relative made that call.

The woman, later identified as D'Zondria, looked the officer in the eye and said, "I'm OK; tell them I'm OK."

The officer asked her if she wanted to borrow his phone to call the family herself, and she declined. In retrospect, Wallace's mother believes she may have done so under duress.

When asked whether police believe the shooter may have already been inside the apartment during the welfare check, Ernster said investigators are "exploring all options. Everything is on the table."

St. Paul's SWAT team arrested the 26-year-old person of interest around 7:30 p.m. Sunday in the 2100 block of Wilson Avenue, where he'd been hiding in an apartment building. Axtell announced the development on Facebook, praising investigators, "each of whom put their heart and soul into this case."

The man is thought to be known to the family, but police declined to confirm his identity or speculate on a possible motive Sunday night. Charges have not been filed.

Staff writers Randy Furst and Kim Hyatt contributed to this report.