Four students were targeted in the late-night attacks. On Sunday, two young men armed with a knife stole cash and a phone from a student walking alone.
Then early Tuesday, two men with a pellet gun confronted three students walking to their dorms. The robbers fled without taking any property, according to Stony Brook University Police Chief Robert Lenahan.
In both cases, the robbers made their move on isolated pedestrian paths on the north side of Stony Brook's sprawling campus. Lenahan said police are investigating whether the robberies are connected based on their locations and the physical description of the suspects.
For students beginning a new semester, the news added an unusual level of anxiety on what many described as a safe campus.
According to New York state crime statistics, the main campus at Stony Brook saw seven robberies between 2009 and 2011.
"I always felt safe but for this to happen twice in a short amount of time is scary," said student Jaclyn Lattanza.
Police are urging students to take precautions, like traveling in groups and staying away from isolated areas late at night. Students promised to heed that advice.
"I'll try to stay inside more and not go out late," said student Jessica Suarez.
According to investigators, both suspects are between 18 and 20. One stands about 6 feet tall; the other about 5 feet 10 inches.
In Tuesday's robbery, the men covered their faces with ski masks.
"We are a small city out here," said Lenahan. "Fifty-thousand people on a daily basis. By and large, this is a highly unusual incident."
For some, however, the robberies served as what one student described as a "wake up call."
"It felt like everyone here was family," said student John Townsend.
"It was home here. To see that happen, it kind of changes my feeling a little bit."