The manhunt for the two Boston marathon bombing suspects ended with the death of one and the capture of the second.
Pictures of the two male suspects were released three days after the bombing.
The maps below explain the twists and turns of what was a massive police operation, lasting almost 24 hours .
1: A police officer is found with fatal gunshot wounds close to the nearby Massachusetts Institute of Technology campus at 22:30 on Thursday (03:30 GMT on Friday).
2: Boston police say Dzhokhar and Tamerlan Tsarnaev hijack a black Mercedes SUV at gunpoint shortly after. They release the driver unharmed.
3: Police chase the car towards Watertown, west of Cambridge. One suspect is fatally injured and the other flees after an exchange of gunfire.
4: Dzhokhar Tsarnaev is found hiding in a boat in a residential backyard late on Friday. He is seriously wounded and taken to hospital.
Cambridge shooting and carjacking: 22:00-01:00
A campus police officer responding to reports of a disturbance near the MIT campus is found shot in his car at about 22:30 local time. He later dies of his injuries.
The suspects, Dzhokhar and Tamerlan Tsarnaev, hijack a car at gunpoint in the 3rd Street area, holding the driver for half an hour until they release him at a petrol station.
Watertown manhunt: 01:00-20:45
The suspects drive the hijacked car towards the Watertown area, west of Cambridge, reportedly throwing explosives at police before the car crashes. They then exchange gunfire with police in the area of Dexter and Laurel Streets.
Tamerlan Tsarnaev is injured and arrested, but dies of his injuries at Beth Israel Deaconess Medical Center at about 01:35 local time. Staff say his injuries include gunshot wounds and trauma that may have been caused by an explosion.
The surviving suspect flees on foot, prompting a massive manhunt and lockdown. Police urge people in Watertown and surrounding areas to stay in their homes.
Swat teams sweep the area for several hours but find nothing and the lockdown is lifted. Less than an hour later a local resident finds Dzhokhar Tsarnaev hiding in a boat in their backyard.
Police exchange gunfire with the suspect and then move in to seize him.