The man suspected of killing the CEO of UnitedHealthcare in Manhattan on Wednesday morning arrived in New York City last month via a Greyhound bus from Atlanta, law enforcement sources told Fox News.
The shooter boarded a bus in Atlanta the day before Thanksgiving, sources within the New York Police Department said.
Brian Thompson was gunned down by the suspect before 7 a.m. Wednesday outside of the Hilton in Midtown Manhattan.
"We are fully cooperating with authorities on this active investigation. As it is ongoing, we cannot provide further comment at this time," a Greyhound spokesperson told Fox News Digital.
Police sources told Fox News the suspect dropped a burner phone in an alley after the shooting. Police are looking into data that was on the phone, as well as fingerprints that were left on the device, sources say.
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Police are also looking into a water bottle that was left at a Starbucks near the scene of the murder. Police sources say that DNA from the bottle is being used to build a suspect profile. The suspect is said to have paid in cash at the Starbucks.
Former NYPD inspector and Fox News Contributor Paul Mauro said the type of possibly rare weapon used by the gunman could work to police's advantage, and addressed rumors the suspect may have worked as a hitman.
"The speculation is that it's a hit man, it's a professional killer and all this sort of stuff…I would just hesitate on that and tell people to just be mindful of the fact that professional hitmen primarily exist in the movies. They don't really exist," Mauro told Fox News Digital. Mauro says everything we know at this point is just speculation.
In video obtained by Fox News Digital, Thompson is seen walking down a sidewalk outside the Hilton early Wednesday morning when the masked suspect guns him down before fleeing the scene.
Additional surveillance videos obtained by Fox News Digital from a deli near where Thompson was killed appear to show his killer walking toward the hotel where he was shot that morning.
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The videos show a person with the same build and wearing the same clothing as the suspect walking down 55th Street at 6:19 a.m. toward the Hilton.
The suspect also used a fake ID to check into a hostel before the shooting, police sources told Fox News Digital.
A NYPD source also told Fox News Digital that messages etched onto bullet casings by the suspect were "left behind to make a statement."
Police sources told the New York Post that the words "deny," "depose" and "defend" were written on the live rounds and casings left behind by the assassin after the shooting. Each bullet and casing had just one word written on it.
Fox News Digital's Lorraine Taylor, Ashley Papa and Christina Coulter contributed to this report.
