Cesar A. Sayoc mugshot photo.

The U.S. Department of Justice has filed a complaint against Cesar Altieri Sayoc over his suspected involvement in sending about 13 pipe bomb packages to prominent political figures, including former U.S. President Barack Obama.

Special Agent David Brown of the FBI’s joint terrorism task force signed the document, which brings five charges against Sayoc, including illegal mailing of explosives and assaulting federal officers.

Read the full complaint:

At a Washington, D.C., press conference today, U.S. Attorney General Jeff Sessions called the bomb threats “utterly unaccceptable,” and said the investigation is “a top priority.”

“We will not tolerate such lawlessness, especially not political violence,” Sessions said.

If found guilty, Sayoc could face up to 58 years in prison.