UnitedHealthcare CEO shooting suspect's timeline before, during, after the brazen murder

Luigi Mangione is accused of gunning down UnitedHealthcare CEO Brian Thompson in a crime that gripped the nation.

Mangione, 26, was taken into custody on Dec. 9 in Altoona, Pennsylvania, in connection with the targeted shooting outside a Midtown Manhattan hotel on Dec. 4,.

Here is a timeline of the suspect's whereabouts before, during and after the shooting:

Nov. 18

Mangione's mother filed a missing persons report in San Francisco in November, seeking information about her son, according to two law enforcement sources.

Nov. 24

The killer entered New York City by bus on Nov. 24, when a surveillance camera at Port Authority Bus Terminal caught his arrival at 9 p.m., law enforcement sources told ABC News.

The inbound bus originated in Atlanta but it was not immediately clear where the suspect boarded.

He likely checked into a hostel on New York City's Upper West Side that day and later checked out, sources said.

Nov. 30

The suspect likely checked back into the HI New York City Hostel on the Upper West Side on Nov. 30, sources said.

Dec. 4 at 5:34 a.m.

At 5:34 a.m., about one hour before the shooting, Mangione left the hostel and rode an e-bike to Midtown, prosecutors said.

Dec. 4 at 6:15 a.m

At about 6:15 a.m., the suspect bought a water bottle and granola bars at a Starbucks at 1290 Sixth Avenue in Midtown, prosecutors said.

Dec. 4 at 6:19 a.m.

Cleared CCTV video shows a man who appears to be the suspect walking west on 55th Street at 6:19 a.m. The video shows him stoop down as he appears to momentarily drop an object on the garbage before continuing to walk.

Dec. 4 at 6:29 a.m.

The suspect appeared to walk past a parking lot on West 54th Street at 6:29 a.m. -- across the street some 50 meters from the site of the shooting.

Dec. 4 at 6:44 a.m.

From 6:38 a.m. to 6:44 a.m., the masked gunman stood against a wall on the north side of West 54th Street across from the New York Hilton Midtown, prosecutors said.

At 6:44 a.m., the masked gunman fatally shot Thompson in front of the north entrance to the Hilton, police said.

"The shooter then walks toward the victim and continues to shoot," NYPD Chief of Detectives Joseph Kenny said. "It appears that the gun malfunctions, as he clears the jam and begins to fire again."

The shooter fled on foot into an alley, where a phone believed to be linked to the suspect was later recovered, police sources said.

Time unknown

The suspect then fled north on a bike and rode into Central Park, police said.

Time unknown

After making his getaway on a bike, the suspect exited Central Park at 77th Street and Central Park West.

At 86th Street and Columbus Avenue, the suspect ditched the bike and took a taxi to the Port Authority bus facility at 178th Street, by the George Washington Bridge.

At first, investigators believed Mangione then boarded a bus at that Port Authority terminal, where investigators said he was spotted on security cameras being dropped off by the taxi. But there was no imagery of Mangione actually getting onto a bus, sources said.

Police sources told ABC News there's video evidence that shows Mangione left the George Washington Bridge bus station, went south to Penn Station and left New York City by train to Philadelphia.

Mangione then spent several days traversing the state from Philadelphia to Pittsburgh, according to Pennsylvania authorities.

Dec. 8

On Dec. 8, FBI agents and NYPD detectives spoke to Mangione's mother after San Francisco police informed them she had filed a missing persons report and Mangione's photo seemed to match the suspect photo, law enforcement sources told ABC News.

Dec. 9

On Dec. 9, 26-year-old Mangione was identified and taken into custody in Altoona, Pennsylvania, authorities said.

Prior to his arrest, Mangione was on a Greyhound bus traveling through Altoona, sources said. When he got off the bus and walked into a McDonald's, a witness recognized him from the images of the suspect circulated by police.

Dec. 17

On Dec. 17, the Manhattan district attorney announced new charges against Mangione, including first-degree murder in furtherance of terrorism.

He is also charged in New York with: two counts of second-degree murder, one of which is charged as killing as an act of terrorism; two counts of criminal possession of a weapon in the second degree; four counts of criminal possession of a weapon in the third degree; one count of criminal possession of a weapon in the fourth degree; and one count of criminal possession of a forged instrument in the second degree.

Mangione remains in the custody of the Pennsylvania Department of Corrections pending his extradition to New York.