After fruitlessly pursuing one of the world's leading drug lords for years, police finally drew close to Joaquin "El Chapo" Guzman using a mobile phone found at a house where drugs were stored.
The phone belonging to a Guzman aide was recovered with clues from a US wiretap and provided a key break in the long chase to find Guzman.
Another big leap forward came after police analysed information from a different wiretap that pointed them to a beachfront flat where the infamous leader of the Sinaloa cartel was hiding.
When he was at last taken into custody with his beauty-queen wife, Guzman had a military-style assault rifle in the room, but he did not go for it.
A day after the arrest, it was not yet clear what would happen next to Guzman, except that he would be the focus of a lengthy and complicated legal process to decide which country gets to try him first.
The mobile phone was found on February 16 at the house Guzman had been using in Culiacan.
By early the next day, the Mexican military had captured one of Guzman's top couriers, who promptly provided details of the houses Guzman and his associates had been using, the officials said.
At each house, the Mexican military found the same thing - steel reinforced doors and an escape hatch below the bathtubs.
Each hatch led to a series of interconnected tunnels in the city's drainage system.
Officials said troops who raided Guzman's main house in Culiacan chased him through the drainage pipes before losing him in the maze under the city.
A day later, on February 18, Guzman aide Manuel Lopez Ozorio was arrested and told investigators that he had picked up Guzman, cartel communications chief Carlos Manuel Ramirez and a woman from a drainage pipe and helped them flee to Mazatlan.
When he was finally in handcuffs, the man who eluded Mexican authorities for more than a decade looked pudgy, bowed and middle-aged in a white button-down shirt and beltless black jeans.
Now 56, he had successfully eluded authorities since escaping from prison in 2001 in a laundry truck.
He is likely to face a host of charges in Mexico related to his role as the head of the cartel, which is believed to sell cocaine, marijuana, heroin and methamphetamine in some 54 countries.
He also faces extensive allegations in the US, where grand juries in at least seven federal district courts, including Chicago, San Diego, New York and Texas, have indicted him.
Officials in Chicago were among the first to say they wanted to try Guzman, followed by prosecutors in Brooklyn, New York.
Assistant US Attorney Steven Tiscione in Brooklyn said it would be up to Washington to make the final call.
During his 13 years on the run, Guzman was rumoured to live everywhere from Argentina to Mexico's "Golden Triangle," a mountainous, marijuana-growing region straddling the northern states of Sinaloa, Durango and Chihuahua.
Under his leadership, the cartel grew deadlier and more powerful, taking over much of the lucrative trafficking routes along the US border.
Guzman watched from western Mexico's rugged mountains as authorities captured or killed the leaders of every rival group challenging Sinaloa's perch at the top of global drug trafficking.
The stocky son of a peasant farmer even achieved a slot on the Forbes' billionaires' list and earned a folk legend status as being too powerful to catch.
Then, late last year, authorities started closing on his inner circle.
The son of one of his two senior partners, Ismael "Mayo" Zambada, was arrested at a border crossing in Arizona in November as part of a sprawling, complex investigation involving as many as 100 wiretaps.
A month later, one of the Sinaloa cartel's main lieutenants was gunned down by Mexican helicopter gunships in a resort town a few hours' drive to the east.
Less than two weeks later, police at Schipol Airport in Amsterdam arrested one of the cartel's senior assassins, a man who handled transport and logistics for Guzman.
The noose got tighter this month. Federal forces began sweeping through Culiacan, capital of the Pacific coast state of Sinaloa, where they closed streets, raided houses, seized automatic weapons, drugs and money, and arrested a series of Zambada associates.
On February 13, a man known as "19," who officials called the new chief of assassins for Zambada, was arrested with two other men on the road to the coastal resort city of Mazatlan.
Four days later, a man described as a member of the Sinaloa cartel's upper ranks was seized along with 4,000 hollowed-out cucumbers and bananas stuffed with cocaine.
Then a 43-year-old known by the nickname "20" and described as Zambada's chief of security was arrested transporting more cocaine-stuffed produce.
By the middle of the week at least 10 Sinaloa henchmen had been seized. And agents learned that Guzman had started coming down from his isolated mountain hideouts to enjoy the comforts of Culiacan and Mazatlan.
Marines closed the beachside road in front of the Miramar apartments, a 10-storey building with white balconies overlooking the Pacific and a small pool in front.
Smashing down the door of an austerely decorated fourth-floor condo, they seized Guzman a few minutes after sunrise.