A surveillance camera captures Times Square before the bomb threat alert
A disposable mobile phone reportedly led FBI agents to Faisal Shahzad, the suspect arrested on Monday night for allegedly driving a car bomb into New York's Times Square.
Reports suggest law enforcement officials initially tracked Mr Shahzad by recovering his mobile, or cell, phone number from the previous owner of the Nissan Pathfinder vehicle used in the attempted bombing.
Officials inserted Mr Shahzad's number into databases to find his name.
Mr Shahzad was arrested late on Monday night at JFK Airport in New York after boarding a commercial flight bound for Dubai.
"They were able to basically get one phone number and by running it through a number of databases, figure out who they thought the guy was," a senior FBI official told the US news website Politico.com.
Details of exactly how government officials may have used cell phone tracking to find Mr Shahzad have not been released.
But analysts say that the identities of mobile phone users can be easily discovered using certain processes.
"Whether you're using a disposable phone or a phone linked to an identity, there is a centralised database of activated numbers," said Nathan Freitas, the lead investigator on the Guardian Project, a non-profit effort to build secure smart phones and investigate mobile phone privacy issues.
Mobile phone carriers use databases for billing purposes and to track a cell phone's usage.
Mobile phones are in constant communication with mobile phone towers. Where the phones are can be determined using simple trigonometry.
The location is triangulated by looking at the position of the phone between two mobile phone towers and analysing its proximity to a third tower.
The angles formed between the phone and the towers are then calculated to determine a phone's exact location.
As an individual moves, his or her mobile phone connects with the nearest mobile phone tower and the tower authenticates its connection.
"Even if a cell phone is not making a call and is just on, it's connecting to the network - connecting back to the centralised databases, and querying if I have a call or if there are any text messages waiting for me," Mr Freitas said.
If a cell phone carrier grants access to the authorities, these same systems that are used to provide service can be accessed by officials to find the most recent location of a cell phone.
Mr Shahzad reportedly did not have his disposable phone in his possession when he was arrested on Monday night.
Analysts say use of mobile phone tracking has come under increased scrutiny in countries like China, where human rights groups say it is used to keep tabs on dissidents.