MEDFORD, N.Y. — A gunman shot four people inside a pharmacy in a New York suburb Sunday morning, killing everyone inside the store in what police said looked like a robbery gone wrong.

The massacre happened at about 10:20 a.m. inside a family-owned pharmacy in a small cluster of medical offices in Medford, a middle-class hamlet on Long Island about 60 miles east of New York City.

Police rushed to the scene after getting a 911 call from someone in the pharmacy’s parking lot. When they arrived, they found two employees and two customers dead, said Suffolk County Police Department’s Chief of Detectives Dominick Varrone. No one inside the shop survived.

Suffolk County Police identified the dead employees as Raymond Ferguson, 45, of Centereach, and Jennifer Mejia, 17, of East Patchogue. Bryon Sheffield, 71, of Medford, and Jamie Taccetta, a 33-year-old woman from Farmingville, were identified as the two customers.

Rene Mejia, of Medford, said one of the victims was his daughter, Jennifer. He said she worked part-time at the pharmacy while attending Bellport High School, where she was finishing her senior year.

“I don’t know what happened,” he said. “She was supposed to graduate Thursday.”

The pharmacy, Haven Drugs, had opened for business at 10 a.m., and Varrone said investigators’ initial belief was that a single gunman was responsible for the bloodbath, and that the motive was robbery. Just how the shooting unfolded, and why, were unclear, he said.

Police said the suspect was armed with a handgun and stole prescription drugs from the pharmacy before fleeing with a black backpack. No suspects were in custody.

A call left for the man listed in state records as the pharmacy’s owner and chief pharmacist, Vinoda Kudchadkar, wasn’t immediately returned.

Police had the streets around the pharmacy blocked off with crime tape. Officers could be seen scanning the ground for evidence, and as of late afternoon the bodies had yet to be removed.

Two teens, who said they were classmates of Mejia, came to the scene after hearing about the shooting from friends on Facebook.

"She was a walking angel on earth," said Kimberly Jimenez, 18, of Brookhaven.

"She gave me a bracelet and said God would watch out for me, Jimenez said. "Why couldn't God watch out for her."

Another classmate, Taylor Lee, 17, of East Patchogue, described Mejia as a "very holy girl."

"She was truly one of God's angels," Lee said.

News of the shootings stunned neighbors, who said they heard the commotion after police arrived, but saw nothing of the crime.

"It's absolutely crazy. There are no words," said Scott Radice, who lives four houses up the street from Haven Drugs and said he has been a customer for 15 years. "I'm hoping they had cameras in the pharmacy so they can catch this guy."

"This is a family business. Everyone goes there. It is our neighborhood pharmacy," said neighbor Kathy Culhane. "If you had a problem with prescriptions, he'd go to bat for you," she said of the owner, who wasn't at the pharmacy when the shooting happened.