Authorities on Long Island say a 53-year-old man is facing a murder charge after his estranged wife, a mother of three, was found dead with chemical burns to her face — the result of what investigators are calling a premeditated and deeply personal attack.

The victim, 46-year-old Aleena Asif, was discovered inside her Nassau County home on October 17 after her teenage daughter called police to report that her younger sibling, age seven, had not been picked up from school. Officers arrived at the house to find Asif dead and her estranged husband, Asif Quereshi, also at the scene. Investigators say Quereshi had broken into the home earlier that morning, waited for the children to leave for school, and then carried out the killing.

Detectives believe Asif was attacked with a corrosive substance that caused fatal chemical burns and asphyxiation. Nassau County Police said Quereshi appeared to have used the same chemical on himself, though his injuries were not fatal.

Asif, who was in the process of divorcing Quereshi, called authorities at least four times to report harassment and threats. “He refused to accept those divorce papers and started showing up at her house,” Detective Capt. Stephen Fitzpatrick said at a press briefing.

Fitzpatrick added that Quereshi had allegedly exhibited “a pattern of stalking” and once threatened to make Asif “swallow bleach.” Investigators now believe that threat may have foreshadowed the method of her death.

Quereshi, an unemployed software engineer, was arrested and charged with second-degree murder. He has pleaded not guilty. Court records reviewed by PEOPLE show he is currently being held without bail pending further proceedings.

Family members described Asif as a devoted mother and a determined professional. “She was a very beautiful human being and very hard working,” one relative told CBS News. “She didn’t deserve this kind of death.”

Neighbors in the quiet Long Island community said they were stunned by the crime. “You’d see her with the kids — always polite, always smiling,” one resident said. “You’d never think something like this could happen here.”

Authorities said the murder underscores the ongoing dangers victims face when trying to leave abusive relationships. National statistics show that nearly half of all women killed by intimate partners are murdered within months of separation. Nassau County officials urged anyone experiencing domestic violence to reach out for help rather than face escalating threats alone.

“This was a woman doing everything she could to protect herself and her children,” Fitzpatrick said. “She went to police. She was trying to build a new life. And even then, the violence found her.”

The case remains under investigation as forensic specialists test the substance used in the attack.

If convicted, Quereshi faces 25 years to life in prison.