Authorities in Montgomery County are looking for a 24-year-old West Philadelphia woman accused of killing her mother’s fiancé on New Year’s Eve after a domestic dispute.

Samiyah Williams allegedly shot and killed Adrionne Reaves, 49, in the lobby of the Delwyn Apartments in Bala Cynwyd on Friday night, according to an investigation between Montgomery County District Attorney Kevin Steele’s office and the Lower Merion Police Department. The D.A.’s Office said the shooting occurred in front of Williams’ mother, Joi Furman; Williams’ grandmother, Florence Furman; and Reaves’ daughter.

The investigation found that after an argument between Joi Furman and Reaves, Joi Furman called Florence Furman that night, saying, “Adrionne laid hands on me.”

The Lower Merion police had responded to a domestic dispute call at the Delwyn Apartments earlier that evening, during which Furman and Reaves agreed to separate for the rest of the night. The couple said the dispute was verbal, according to the D.A.’s Office.

The investigation found that Reaves’ daughter picked Reaves up from a nearby Lord & Taylor, but they later returned to the Delwyn Apartments to find Reaves’ keys, at which point they saw Joi and Florence Furman. The D.A.’s Office said lobby surveillance video shows the Furman women, Reaves’ daughter, and Reaves walking through the lobby when Reaves collapses to the floor.

“Seconds later, a thin person dressed in black with a dark hood pulled up” — believed to be Williams -- “exits the lobby and leaves the area,” the D.A.’s Office said.

Williams has a permit to carry a concealed gun in Philadelphia and owns a 9mm semiautomatic Walther handgun, detectives found. She has been charged with first-degree murder, third-degree murder, and possessing an instrument of crime.

It was not immediately clear Saturday night whether she had retained a lawyer.