Cesar Sayoc: How US authorities used one fingerprint to catch serial pipe bomb suspect

Fingerprint on package sent to lawmaker Maxine Waters helped officials identify Cesar Sayoc

It took less than five days for US law enforcement officials to identify the man they believe was responsible for sending at least 13 pipe bombs to political opponents of President Donald Trump.

Mobile phone data, DNA records, spelling mistakes and a single fingerprint all played a part in leading to the arrest of Cesar Sayoc at a parking lot in Plantation, Florida.

Mr Trump said investigators had done “an incredible job” in bringing in a suspect so quickly after a string of suspicious packages were discovered at homes and offices in New York, Florida and California.

The FBI, the Joint Terrorism Task Force and local police officials worked swiftly to untangle clues this week as the number of packages containing potentially explosive material mounted.

The big break came when a single fingerprint found on a package intended for California lawmaker Maxine Waters matched a fingerprint of Mr Sayoc’s on file with Florida authorities.

A DNA sample from a device intended for former president Barack Obama similarly matched the suspect’s DNA, the FBI revealed.

An FBI agent investigates the van believed to belong to Cesar Syoc (AFP/Getty) (AFP/Getty Images)

An additional clue came in the spelling errors found on the packages which matched misspellings made on Mr Sayoc’s online posts, according to an 11-page criminal complaint that included the formal charges of threatening former presidents and transporting explosives across state lines.

Five packages were traced back to the Opa-Locka distribution centre just outside of Miami, in the days after they were sent.

And mobile phone geolocation information was also used to track him to Plantation, a small city six miles outside Fort Lauderdale.

Around 50 armed officers swarmed Mr Sayoc as he approached a white van in the parking lot outside an auto parts store. They ordered him to the ground and he did not resist.

Cesar Sayoc is escorted from an FBI facility in Miramar, Florida (Reuters) (REUTERS)

“He had that look of, ‘I’m done, I surrender’,” said witness Thomas Fiori, a former federal law enforcement officer who watched from across the street.

FBI Director Christopher Wray hailed the “unbelievable” work of investigating officials. “This is phenomenal work with the greatest pressure under an incredibly tight time frame.”

New packages addressed to New Jersey senator Cory Booker and former National Intelligence director James Clapper were intercepted. Packages had been sent to Mr Obama, former vice president Joe Biden, Hillary Clinton, George Soros and the cable network CNN earlier this week.

Investigators are still examining the material found in more than a dozen packages. They have been found to contain timers, batteries, shrapnel and PVC pipes up to 6 inches in length.

Although they were not rigged to explode upon opening, authorities noted that they included “energetic material”.

A footnote to the charging document said such explosive material “gives off heat and energy through a rapid exothermic reaction when initiated by heat, shock or friction”.

Some of the packages included photographs of the intended recipients marked with a red “x”.

“Today’s arrest does not mean we are all out of the woods,” Mr Wray warned on Friday. “There may be more packages in transit now.”

FBI officials are also probing for a motive behind the mail bomb spree. Attorney General Jeff Sessions has suggested politics may have played a role, noting that Mr Sayoc appeared to be a “partisan.”

Photos and video found on Mr Sayoc’s social media accounts showed he attended Trump rallies, wore a “Make America Great Again” hat and shared far-right conspiracy theories.