New York (CNN) -- Police have arrested Long Island resident David Laffer in the deaths of four people shot inside a pharmacy Sunday morning.
Laffer, 33, is accused of shooting two employees at Haven Drugs in Medford as well as two customers before leaving with prescription drugs, according to a statement released Wednesday by Suffolk County Police.
He has been charged with first-degree murder and resisting arrest, police said.
Laffer's wife, Melinda Brady, 29, was also arrested. She was charged with third-degree robbery and obstructing governmental administration, authorities said.
Both Laffer and Brady will be arraigned Thursday at First District Court in Central Islip, Long Island.
Police identified the dead as Raymond Ferguson, 45, and Jennifer Mejia, 17, both pharmacy employees, as well as customers Bryon Sheffield, 71, and Jamie Taccetta, 33.
Mejia's death comes just before her prom -- scheduled for Wednesday night -- and her graduation from Bellport High School on Thursday, said school secretary Maryann Malcolm.
CNN's Rachel Garrett, Jason Kessler, Max Markham and Jordana Ossad contributed to this report.