Although it has not yet been determined whether the suspect in custody in the mailing of explosive devices to critics of President Donald Trump will be charged with terrorism, at least one analyst asserts that this week’s spate of mail bombs can be labeled as such for several reasons. Randall Rogan, an expert on terrorism and hostage negotiation and a professor of communications at Wake Forest University in Winston-Salem, N.C., laid out his logic: "I would define these acts as domestic terrorism — terrorism being defined as acts of violence or threat of violence against non-combatants for political reasons, with ‘political’ being used very broadly to be inclusive of religious, social and other ideological purposes, and this is domestic in nature." Rogan admitted, though, "The definition of terrorism is vague, with no truly universally accepted definition." The Patriot Act, passed in 2001 after the Sept. 11 terrorist attacks, defines domestic terrorism as activities on U.S. soil that "involve acts dangerous to human life" and "appear to be intended to intimidate or coerce a civilian population; to influence the policy of a government by intimidation or coercion; or to affect the conduct of a government by mass destruction, assassination or kidnapping." Previous mail attacks Attacks through the U.S. mail are anything but new. The U.S. Postal Service has long been used to send suspicious packages to high-ranking U.S. officials. William Clyde Allen, a U.S. Navy veteran, was charged this week on seven counts for sending letters containing ricin, a highly toxic substance, to Trump and other high-ranking U.S. officials. Officials confirmed the letters were mailed earlier in October. In March 2018, two people were killed when explosive packages arrived at their residences in Austin, Texas. Mark Anthony Conditt, 23, who blew himself up when police closed in on him, was identified as the Texas bomber. In 2013, Shannon Guess Richardson, a Texas actress, sent ricin-laced letters to then-President Barack Obama and then-New York Mayor Michael Bloomberg. She was sentenced to 18 years in prison. The sentence was on charges of attempting to use biological weapons. That same year, James Everett Dutschke mailed similar letters to Obama and other U.S. officials. He was later sentenced to 25 years in prison. (Ricin is a naturally occurring toxin found in castor beans. If inhaled, ingested or injected in a refined form, ricin can kill a person within 48 hours of exposure. According to the U.S. Centers for Disease Control and Prevention, there is no antidote for ricin.) One of the the most prominent mail attacks occurred in 2001, days after the 9/11 terror attacks. Several letters containing anthrax bacterial spores were mailed to offices of news organizations and U.S. lawmakers. The attacks killed five people and injured 17 others. Bruce Edwards Ivins, a former government scientist, committed suicide in 2008 while the FBI was investigating his involvement in the case. Following his death, the FBI announced that Ivins was the only suspect in the anthrax attacks, also known as Amerithrax from its FBI investigation case name. And the infamous Ted Kaczynski, known as the Unabomber, prompted the longest FBI investigation ever before his capture in 1996, but only after killing three people and injuring another 23. The anarchist went after those involved with technology and was regarded as a domestic terrorist, but he was found guilty of other charges. Domestic terrorism None of the individuals involved in those cases was convicted of terrorism, while terror charges have been brought against people affiliated with known international terrorist organizations. The Patriot Act primarily grants the Justice Department the authority to investigate an individual or a group affiliated with a group that the State Department has listed as a foreign terrorist organization. According to federal law, in order to be charged with terrorism, a person must be suspected of acting on behalf of one of those listed groups. Some analysts, like David Sterman of the Washington-based think tank New America, believe the issue of domestic terrorism is debatable, and it is viewed as a sensitive matter. "There are laws that deal with domestic terrorism-related acts, but the reason we don't have a specific law on domestic terrorism is mainly political sensitivity in this country," Sterman said. "The difference between hate crimes and terrorist acts has always been a controversy in the U.S." Other experts say current federal laws pertaining to acts of political violence are adequate. "Our current laws dealing with political violence are sufficient in terms of giving long sentences to the perpetrators," said Karen Greenberg, director of Center on National Security at Fordham Law, a nonpartisan research group. "I don't think we need a new law that could add more to the sensitivity. The Obama administration had some interest in creating a federal charge for domestic terrorism, but again it didn't get anywhere because of the political climate," Greenberg said. In September 2017, Trump signed into law a congressional joint resolution that condemned the violence in Charlottesville, Va., where a speeding car slammed into counterprotesters, killing one person and injuring 19 others. The resolution called the incident a domestic terrorist attack.