A timeline of the fatal shooting of UnitedHealthcare CEO Brian Thompson and search for his killer

NEW YORK — After days of searching through security footage, following up on a deluge of tips and even sending scuba divers to the bottom of a lake, police on Monday announced the arrest of a suspect in the killing of UnitedHealthcare's CEO outside a Midtown Manhattan hotel last week.

The hunt began in the hours after Brian Thompson was gunned down on the sidewalk early Wednesday morning, with the suspected shooter slipping away from the scene and riding a bike to Central Park, before taking a taxi to a bus depot that offers service to several nearby states.

On Monday morning, a tip from a McDonald’s around 233 miles (375 kilometers) away in Altoona, Pennsylvania, led police to arrest 26-year-old Luigi Nicholas Mangione, who authorities say was carrying a gun believed to be the one used to shoot Thompson.

Here's what we know so far about the shooting and subsequent search.

Nov. 24

10:11 p.m. — The suspected shooter arrives in New York City on a Greyhound bus at the Port Authority terminal. The bus originated in Atlanta and made six or seven stops on the way to New York. Police could not immediately determine where he got on the bus.

The man then takes a taxi to the area of the New York Hilton Midtown and is there for about a half hour.

About 11 p.m. — The man takes a taxi to the HI New York City Hostel at 891 Amsterdam Ave., where he stays until the morning of the shooting. He presents an ID that police believe to be fake. Two roommates in a shared room that had bunkbeds never saw his face, police said, because he kept his mask on.

When speaking with an employee in the hostel lobby, he briefly pulled down his facemask and smiled — a moment captured on surveillance images that have been widely circulated by police.

Nov. 29

The man was checked out of the hostel, where guests are automatically checked out if they don’t show at the desk by a certain time. Police don’t believe he stayed someplace else and checked back into the same hostel the next day.

Dec. 4

About 5:30 a.m. — The suspected shooter leaves the hostel well before dawn.

5:41 a.m. — He appears on video at 54th Street and Sixth Avenue walking back and forth in the area of the Hilton hotel where United Healthcare’s parent company, UnitedHealth Group, is holding its annual investor conference.

Police deduce that he rode a bicycle to the Hilton because it took him such a short time to get there. “Could he have stolen the bike? These are things we’re still looking into,” NYPD Chief of Detectives Joseph Kenny said.

At some point, he went to a nearby Starbucks and purchased a bottle of water and at least one energy bar before returning to the hotel.

6:44 a.m. — He shoots Thompson as the executive arrives alone, on foot, having walked from a hotel across the street. The man flees.

6:48 a.m. — The man enters Central Park by bicycle at the 60th Street and Center Drive entrance. It's in the park and away from security cameras that police believe he discards a gray backpack.

6:56 a.m. — He leaves the park at West 77th Street and Central Park West, still on the bicycle.

6:58 a.m. — He passes another camera on 85th Street and Columbus Avenue, still on the bicycle.

7 a.m. — He's at 86th Street, no longer with the bicycle.

7:04 a.m. — He enters a taxi northbound at 86th Street and Amsterdam Avenue.

7:30 a.m. — He's near the George Washington Bridge and the bus terminal there. It offers commuter service to New Jersey and Greyhound routes to Philadelphia, Boston and Washington.

After the attack, investigators find the words “delay," “deny” and "depose,” written in permanent marker on ammunition at the scene. The words mimic a phrase used by insurance industry critics.

Dec. 6

Kenny and Police Commissioner Jessica Tisch reveal that investigators believe the gunman left New York City on a bus. Investigators say he entered the George Washington Bridge Bus Station but have not found video of him leaving or getting on a bus.

“It could possibly be a disgruntled employee, or a disgruntled client," Kenny says of a possible motive in a briefing.

Police find what they say is the man's backpack. Its contents are not disclosed.

Dec. 7

Police continue to search Central Park; scuba divers are seen scouring a pond. The NYPD releases additional photos showing the suspected shooter next to and in the back seat of a taxi. In both images he is seen wearing a blue, medical-style face mask.

Despite recovering a fingerprint from the Starbucks purchase and sending items for DNA testing, police have yet to publicly identify the suspect.

Dec. 8

Scuba divers are again seen at a Central Park pond. Police decline to comment on the investigation.

Dec. 9

9:14 a.m. — Police in Altoona, Pennsylvania, are dispatched to a McDonald’s to respond to reports of a male matching the description of the suspect in the shooting.

Luigi Nicholas Mangione, 26, is taken into custody on unrelated charges, according to the Altoona Police Department.

Mangione had a gun believed to be the one used in last Wednesday’s shooting, as well as writings suggesting “ill will toward corporate America,” Kenny said on Monday. He also had clothing and a mask similar to those worn by the shooter and a fraudulent New Jersey ID matching the one used to check into the Manhattan hostel, Kenny said.