Authorities are reportedly questioning a man in central Pennsylvania in relation to UnitedHealthcare CEO Brian Thompson’s killing, marking the latest development after what police said was a “brazen targeted attack” on the health insurance executive in Manhattan last week.

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$50,000. That’s how much the FBI, which announced it had joined the investigation, is offering for information leading to the gunman’s arrest. The NYPD has offered a reward of up to $10,000.

Thompson was shot in the back and right calf outside of the New York Hilton Midtown just before 7 a.m. Wednesday morning and was rushed to Mount Sinai West in critical condition, where he was pronounced dead. Video footage of the shooting shows the suspect walking behind Thompson, who was wearing a blue suit and appeared to be heading to the Hilton hotel alone. Thompson didn’t have a security detail and left his hotel alone, said Joe Kenny, the New York City Police Department’s chief of detectives, citing UnitedHealth employees. The suspect had checked out of the New York International Hostel in the Upper West Side Wednesday morning, The New York Times reported, and visited a Starbucks—where he reportedly bought the water bottle police found—near the Hilton before waiting outside of the hotel.

Police reportedly believe the suspect arrived in New York in late November on a bus that left from Atlanta—though they don’t know where he boarded it. He then reportedly checked into a hostel at some point, checked out on Nov. 29, and checked back in on Nov. 30. A senior law enforcement official told The New York Times the shooter used a fake New Jersey ID to book a room at the hostel, and he reportedly used cash during his time in the city. The Atlanta Police Department confirmed in a statement it began assisting the NYPD in its investigation on Friday afternoon.

No. The suspect, who fled first on foot then on an electric bike, was last seen in Central Park and is still at large, NYPD commissioner Jessica Tisch said. He is believed to be a light-skinned man who was wearing a light brown or cream-colored coat, black and white sneakers, a black face mask and a “very distinctive” gray backpack, Kenny said. New Yorkers should “go about their daily lives” but “be alert,” NYPD chief of department Jeffrey Maddrey said Wednesday.

The police have found a burner phone, a water bottle and protein bar that were reportedly bought at the nearby Starbucks the suspect visited, and a backpack that reportedly contained Monopoly money and a Tommy Hilfiger jacket. Officers at the scene also found bullet casings with a message written on them. Detectives obtained DNA evidence that is now being examined by the Office of the Chief Medical Examiner, The New York Times reported Friday, but it’s unclear where the DNA was taken from and whether it will match existing DNA in a law enforcement database. Meanwhile, investigators are reportedly looking into the purchase of a gun in Connecticut to determine whether the suspect could have bought it, the Times reported.

Officers found three 9mm rounds at the scene, Kenny said. Casings that were found at the site of the shooting had the words “deny,” “defend” and “depose” written on them, ABC News first reported Thursday, citing anonymous police sources. Though police have not named a motive in the killing, the words echo a common phrase—“delay, deny, defend”—describing allegations thrown at insurance companies that are accused of avoiding paying claims whenever they can. UnitedHealthcare and and other health insurance companies “have become frequent targets of criticism” for denying claims and making it harder to get care, the Associated Press reported earlier this year.

Police think so. The gunman was “lying in wait for several minutes” and ignored other passers-by before approaching and firing at Thompson from behind as he walked to the hotel, Tisch said Wednesday. Tisch called the shooting a “brazen targeted attack” that did not appear to be a random act of violence, and “every indication” pointed to a “premeditated, pre-planned targeted attack.” Thompson’s wife Paulette Thompson told NBC News Wednesday that while she did not know specific details, she was aware that “some people had been threatening him.” While the motive behind the attack is still unknown, the suspect appeared to be “proficient in the use of firearms” as he was able to clear a malfunction in the gun, Kenny said. Footage of the shooting shows there was another person present when the suspect raised his weapon at Thompson, who fled.

Thompson–a Minnesota resident–was in New York for an investor meeting for UnitedHealthcare parent UnitedHealth Group, which was halted abruptly Wednesday after UnitedHealth Group CEO Andrew Witty said the company was “dealing with a very serious medical situation,” according to Bloomberg. UnitedHealth Group said it was “deeply saddened and shocked at the passing of our dear friend and colleague” in a statement issued Wednesday, and said it was working closely with the police.

Who Is Brian Thompson? UnitedHealthcare CEO Fatally Shot After Being Threatened (Forbes)

UnitedHealthcare CEO Fatally Shot In NYC: Police Still Searching For Gunman (Forbes)

‘Deny,’ ‘Defend, ‘Depose’: What To Know About Words Reportedly On Shell Casings Tied To UnitedHealthcare CEO Shooting (Forbes)