A Florida man suspected of sending more than a dozen pipe bombs to prominent critics of President Donald Trump last year pleaded guilty on Thursday.

Cesar Sayoc entered the plea before a federal judge in Manhattan. He had previously pleaded not guilty.

"I know that these actions were wrong and I'm sorry," Sayoc said through tears. Sayoc said that he never intended for the devices to explode, but he acknowledged that he was aware there was a risk they could detonate.

Sayoc, 57, pleaded guilty to 65 counts, including using weapons of mass destruction and the illegal mailing of explosives with intent to kill or injure. He faces up to life in prison. He is being held without bail and is scheduled to be sentenced on Sept. 12.

Cesar Sayoc is seen in a booking photo, in Miami on Aug. 30, 2015. Broward County Sheriff's Office via AP

Sayoc was arrested on Oct. 26. He was charged in what prosecutors have called the “alleged execution of a domestic terrorist attack” that involved mailing 16 improvised explosive devices to 13 victims throughout the country.

None of the bombs detonated and no one was injured.

Sayoc was accused of sending or addressing the devices to a series of high-profile Democrats, including former Secretary of State Hillary Clinton, actor Robert De Niro and philanthropist George Soros, as well as to the CNN headquarters in New York.

When he was arrested in Florida, Sayoc was living out of a white van plastered with stickers praising Trump and attacking the media.

Sayoc said in court Thursday that he made and sent the devices with the intent to threaten and intimidate.

"Cesar Sayoc has admitted to acts of domestic terrorism that are repulsive to all Americans who cherish a society built on respectful and non-violent political discourse, no matter how strongly held one’s views,” Assistant Attorney General for National Security John C. Demers said in a statement.

"Our democracy will simply not survive if our political discourse includes sending bombs to those we disagree with," Demers said.

The van federal agents are investigating in connection with package bombs that were sent to high-profile critics of President Donald Trump is transported on a flatbed tow truck on Friday, Oct. 26, 2018 in Miramar, Florida. Carline Jean / South Florida Sun-Sentinel via AP

Court records last week indicated that Sayoc was expected to plead guilty.

Besides Clinton, Soros, CNN and De Niro, Sayoc allegedly sent or addressed the devices to former President Barack Obama; former Vice President Joe Biden; former Attorney General Eric Holder; former CIA Director John Brennan; Sens. Cory Booker, D-N.J., and Kamala Harris, D-Calif.; Rep. Maxine Waters, D-Calif.; activist Tom Steyer; and former Director of National Intelligence James Clapper.

Shortly after his arrest, law enforcement sources told NBC News that Sayoc had a list of more than 100 potential targets and did online research on political figures, journalists and entertainers.

"For five days in October 2018, Cesar Sayoc rained terror across the country, sending high-ranking officials and former elected leaders explosive packages through the mail," U.S. Attorney for the Southern District of New York Geoffrey S. Berman said in an updated statement that corrected the month.

"Thankfully no one was hurt by these dangerous devices, but his actions left an air of fear and divisiveness in their wake," Berman said.

Prosecutors have said that between Oct. 22 and Nov. 2 the FBI and U.S. Postal Service recovered 16 manila padded envelopes containing improvised explosive devices that were believed to have been sent by Sayoc from Florida.

Each had similar features, including the return address listed as “Debbie Wasserman Shultz,” an apparent reference to U.S. representative and the former head of the Democratic National Committee, Debbie Wasserman Schultz, according to the Justice Department.

The 16 IEDs included approximately six inches of PVC pipe packed with explosive material, a small clock, and wiring, the Justice Department has said, and some of the IEDs also contained shards of glass.

Attached to the outside of the explosive devices was a picture of the intended victim marked with a red "X," officials said.

The bomb scare occurred just days before the Nov. 6 midterm elections in which Democrats took enough seats to gain a majority in the House of Representatives.