BROOKHAVEN, N.Y. (CBSNewYork) -- Police in Suffolk County continued their intense hunt Monday for the gunman behind a deadly Father's Day pharmacy shooting that left four people dead.
At a news conference Monday afternoon, Police Commissioner Richard Dormer said authorities were offering up to a $5,000 reward for information on the suspect, who got away with prescription drugs after the shooting inside Haven Drugs in Medford shortly after 10 a.m. Sunday.
Police are also making a special appeal to doctors and pharmacists in the area to come forward if they may have any leads regarding the suspect. Dormer also issued a word of caution to pharmacies -- especially smaller stores -- to be extra vigilant.
"We believe the suspect is a drug user and should be considered armed and dangerous," Dormer said.
Heartache has blanketed the entire community in Medford.
"It's a huge tragedy to the whole neighborhood," Paisley Taylor, a customer at the pharmacy, told CBS 2's Hazel Sanchez. "It's just so close to home that it makes you wonder how safe you are."
Authorities said the gunman is white, about 5-foot-8 with a thin build, short dark hair and dark facial hair. He was last seen running east on South Haven Avenue wearing a black backpack.
Police have also released new video surveillance photos, caught by recently installed security cameras.
Calling the shooting "the most heinous, brutal crime Suffolk Police have ever encountered," Dormer said the victims offered no resistance and were killed quickly and at close range.
Meanwhile, Jennifer Mejia, who worked at the pharmacy, was a high school senior days away from receiving her diploma when she was shot dead, execution-style.
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The victims' families were trying to cope with the unthinkable as they returned to the scene of the crime.
"She didn't deserve it – not like that," Leslie Mejia, the victim's sister, said. "I know she's an angel watching over us now."
WCBS 880's Peter Haskell has the latest on the tragic slayings.
Mejia's heartbroken father, Rene, was despondent. He remembered their last encounter, when she went off to work.
"She told me 'Happy Father's Day.' I said 'OK.' I feel bad because I didn't even hold her," Rene Mejia said. "She wanted to be a doctor."
Mejia, 17, along with 45-year-old pharmacist Raymond Ferguson, and customers Bryon Sheffield, 71, and Jamie Taccetta, 33, were all shot and killed, execution-style.
Taccetta ran into the pharmacy Sunday, while her fiancee waited outside. He grew worried and discovered the massacre when he went inside to check on what happened.
"It's just devastating. It's like why would that person do something like that? You want the drugs, take it and run. Why kill four people?" Lola Houghton, Ferguson's neighbor, asked.
Pharmacist Howard Levine said his West Babylon pharmacy was robbed twice by a man looking for drugs.
Levine said he no longer carries addictive painkillers like oxycontine and oxycodone. He said he believes pharmacy robberies can be prevented by strengthening drug regulations and record-keeping.
"To identify those people who are excessively prescribing, those people who are excessively dispensing and those people who are excessively using," he said.
The owner of Haven Drugs was supposed to work Sunday morning but decided instead to first go to church. He collapsed after witnessing the scene inside.
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During what is typically the happiest week of a senior's life, there was profound sadness among Mejia's classmates at Bellport High School. Students held a vigil Sunday night.
"Jenn was an angel on Earth and I think I speak for the class when I say she will be dearly missed," said classmate Taylor Lee.
Assistant Principal Bryan Norton was shaken up and said he just spoke with Mejia last week.
"She was an absolute sweetheart, a lovely young lady, looking forward to her future," Norton said. "She was planning on going to Suffolk to continue her studies."
Mejia was to attend prom this week. Her funeral will be on the day she was supposed to graduate. Grief counselors were on hand Monday for Mejia's classmates.
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