Police said the victims were a roommate in Valley Stream and a Wendy’s coworker in Island Park.
MINEOLA, N.Y. — A 22-year-old Valley Stream man was charged Saturday with murder after police said two women he knew were fatally stabbed hours apart at a Nassau County home and a Wendy’s restaurant late Thursday and early Friday.
Rony Yahir Alvarenga Rivera faces one count of first-degree murder and two counts of second-degree murder in the deaths of a 32-year-old woman found inside a Valley Stream home and a 42-year-old woman found outside the restaurant where she worked. Police said the women had not been publicly identified while officials worked to notify relatives. The case has shaken two Long Island communities and left investigators trying to explain why the attacks happened.
Nassau County police said the first killing happened around 9 p.m. Thursday inside a home on West Mineola Avenue in Valley Stream, where Alvarenga Rivera and the 32-year-old woman lived in the same building. Officers later found her during a welfare check early Friday. Police said the second killing was reported at 12:27 a.m. Friday outside a Wendy’s on Austin Boulevard in the Island Park area, where officers found a 42-year-old woman with stab wounds. Nassau County Police Detective Lt. George Darienzo said officers were still at that scene when they learned a man had been stopped near 169 Atlantic Ave. in Lynbrook. “When the police arrived, he said he had killed somebody that night,” Darienzo said.
Police said both women died from multiple stab wounds to the neck and torso. The 42-year-old victim worked at the Wendy’s, and Alvarenga Rivera also worked there, officials said. Police said she was taking out garbage when she was attacked. She was described by officials as a mother of two young children. The 32-year-old victim was found inside the Valley Stream home after officers received information that a second person might have been killed. Darienzo said Alvarenga Rivera and the woman rented bedrooms at the same location and shared common spaces, including a living room, kitchen and bathroom. He said investigators did not know of a specific domestic relationship between them.
Authorities said Alvarenga Rivera knew both victims, but they did not announce a detailed motive. Darienzo, the commanding officer of the Nassau County homicide unit, said investigators were looking at anger as a possible factor, adding, “I’ll sum it up in one word: anger.” He did not give more detail. Police Chief Patrick Ryder said the injuries in both killings were similar. Nassau County Executive Bruce Blakeman said Alvarenga Rivera is from El Salvador and came to the United States as an unaccompanied child about a decade ago. Darienzo said police knew of no gang connection. Officials did not say whether immigration status played any role in the criminal investigation.
Alvarenga Rivera was located by Lynbrook police and arrested without incident after the encounter near the 7-Eleven on Atlantic Avenue, officials said. Police said he was linked to both killings as detectives reviewed the sequence of events and gathered evidence from the two scenes. Reports said he pleaded not guilty after the charges were filed. Police said he was scheduled to be arraigned Saturday, May 2, at First District Court in Hempstead. As of Sunday, officials had not released the victims’ names, a next court date or a full account of what led to each attack. The investigation remained active.
The killings left a quiet block in Valley Stream and a fast-food restaurant in Island Park under heavy attention from police, neighbors and passersby. Investigators worked near the home on West Mineola Avenue, while people near the Wendy’s described a somber scene after learning that one of the victims had died at work. One woman who stopped near the restaurant said she wanted to acknowledge the victim even though she did not know her. “You don’t have to know somebody to feel horrible for what happened,” she said. A Valley Stream resident said the case felt too close to home, while another resident said she was shocked to learn the two crime scenes were connected.
The case stood Sunday with Alvarenga Rivera in custody on murder charges, two families awaiting public identification of the victims and Nassau County detectives continuing to collect evidence. Officials said more information could come after the victims’ relatives are notified and the case moves forward in court.
Author note: Last updated Sunday, May 3, 2026.