Cynelle Brown, 28, was spotted by PAPD Sgt. Kevin Cottrell and Officers Brandon Kubic and James Herkenham, in plainclothes, on the lower level of the terminal's north wing at the Greyhound ticketing area, the authority's Joseph Pentangelo said.
Brown was waiting on line to buy bus tickets to Wilmington, Delaware with "a woman identified as his aunt and the aunt's child" waiting on online, he said.
Recognizing Brown from a photo distributed by the FBI a short time earlier, the officers moved in and seized the unarmed suspect, Pentangelo said.
"He was turned over to the custody of the Tarrytown Police Department," he said.
The 34-year-old victim, whose name wasn't immediately released, was shot just after 7 a.m. at the Sleepy Hollow Gardens complex on White Plains Road, authorities said. She was later pronounced dead at Westchester Medical Center, they said.
Mamaroneck's school district dismissed all its students early, while other districts in and around Tarrytown remained locked down or held in place, as a search for the killer continued.
Irvington, Dobbs Ferry, Ardsley, Hastings-on-Hudson, Elmsford and Tarrytown schools went into lockout mode following the shooting as a precaution.
Police officers remained on school campuses until the end of the school day.
The FBI joined SWAT teams and officers from the State Police, Westchester County, and Greenburgh
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