The sister of a woman police say was killed and left to decay for two weeks in a Queens home in June is begging for the public’s help in tracking down her suspected killer.

Melanie Apostol said she hopes someone will recognize images of 55-year-old Mark Washington, which police released Tuesday as they search for him in connection with the killing of her sister, 38-year-old Angelique Apostol. Police have identified Washington, who was Angelique Apostol’s fiancé, as a suspect in her death.

Officers discovered Angelique Apostol dead inside a house on a tree-lined stretch of 205th Street and 113th Road in St. Albans on June 24, although it was later determined she’d been killed on June 10, according to police. The city medical examiner ruled her death a homicide from a gunshot wound to the head.

Melanie Apostol said her sister’s body was discovered only because neighbors noticed a bad smell and called 911. By that time, she said, her sister’s body was so badly decomposed that she was unrecognizable.

“I had to identify her through my children’s names because she has all my children’s names tattooed on her,” Melanie Apostol told Gothamist through tears on Wednesday. “We couldn’t have an open casket. I couldn’t even see her. They wouldn’t show me her hand or anything.”

Melanie said her sister met Washington on Facebook sometime last year and their relationship developed quickly over the course of several months. The couple often made TikTok videos together, and when Washington proposed to Angelique, she accepted, Melanie said. Angelique would often go stay with Washington at his home in Queens when she wasn’t staying with her family on Staten Island or visiting friends in Upstate New York, Melanie added.

Police said it was unclear what sparked the allegedly fatal violence between the couple.

On June 6, Washington posted a TikTok video of his fiancée in Knicks clothing. Four days later, on the day police say Angelique was killed, Washington posted a video of himself at a gathering with King of Kings Foundation, a Jamaica-based antiviolence organization that he was actively involved with, based on his profile.

King of Kings did not immediately respond to an inquiry about Washington and his involvement in the organization.

NYPD officials said Washington has a criminal record that includes seven felony convictions, meaning he would have been prohibited from legally owning a firearm in New York state.

Melanie Apostol said her sister was a fun-loving woman who “liked to put a smile on people’s faces.” Angelique Apostol had no children of her own, but had recently completed a home health aide course to help take care of two of her sister’s kids, who have special needs.

“We’re not dealing with it well because there was no closure,” Melanie Apostol said. “It’s a disgrace because she loved him, and he claimed he loved her.”

Murders linked to domestic violence are trending down citywide, with 32 recorded through mid-August this year — the lowest number in that timeframe since 2007, according to the NYPD. Over the past three years, police data indicates domestic violence homicides have been steadily decreasing.

But the number of people arrested for domestic violence incidents is up just over 2% so far this year, according to police data. Reports of domestic violence assaults have stayed somewhat consistent with last year’s numbers in the same timeframe, with more than 19,720 incidents reported in 2026 so far.

Police are asking anyone who might have information about Washington to call the NYPD’s Crime Stoppers Hotline at 800-577-TIPS (8477), or 888-57-PISTA (74782) in Spanish. People can also submit their tips on the Crime Stoppers website or via X @NYPDTips.

Anyone experiencing domestic violence in the five boroughs can call New York City’s 24-hour domestic violence hotline at 800-621-HOPE. Survivors can also access resources including Family Justice Centers through the Mayor’s Office to End Domestic and Gender-Based Violence.