As law enforcement officials scramble to identify the individual or individuals behind the explosive devices sent to Democratic politicians, billionaire philanthropist George Soros, and CNN’s New York City newsroom, one former agent with the Bureau of Alcohol, Tobacco, Firearms and Explosives says he’s confident investigators will get to the bottom of it ― eventually.

On Wednesday, authorities recovered suspicious packages targeting Hillary and Bill Clinton, former President Barack Obama, at least two Democratic members of Congress, former Attorney General Eric Holder and CNN’s offices at the Time Warner Center in Manhattan. A similar device was found Monday near Soros’ home in Katonah, New York.

The packages contained pipe bombs that appear to have been made with relatively rudimentary materials. Authorities have confirmed that a number of them contained explosive powder.

This is a photograph of the suspicious package sent to the CNN building in New York City earlier this morning. Police say it appeared to be a live explosive device. https://t.co/aG9JsTfwhx pic.twitter.com/tcICHJErda — CNN Breaking News (@cnnbrk) October 24, 2018

There is no shortage of theories about who might be behind the plot. Considering the targets, many have expressed concern that this could be a coordinated attack on Democrats and the media, frequent foes of President Donald Trump and his supporters. On the other hand, pro-Trump media figures have claimed, without evidence, that it’s part of a Democratic “false flag” conspiracy.

Instead of relying on conjecture, investigators will be looking for clear evidence to help them nail down a culprit, said David Chipman, a former ATF agent who worked on the 1993 World Trade Center attack and the Oklahoma City bombing and now serves as senior policy adviser at the Giffords Law Center to Prevent Gun Violence.

“I know our law enforcement will get to the bottom of it. I just don’t know how long it will take ― I don’t know if there will be other incidents,” said Chipman.

Law enforcement has an advantage because the devices didn’t explode, meaning all of the potential evidence is still fully intact, Chipman added. The first step is to render the bombs safe, ideally without damaging any of the components or materials that hold them together. The approach may depend on how the devices were constructed and what sort of detonation mechanism they contained.

In certain cases, investigators may determine it safe to remotely unscrew caps on devices and simply pour out the explosives, said Chipman. Technicians also have access to water cannons that can disable explosives without introducing unknown chemicals that can ruin potential evidence.

With access to the inside of the bomb, investigators can begin their forensic work. They’ll examine the devices in an effort to identify similarities that might link them back to a single sender or bomb maker, said Chipman. Even if there’s nothing remarkable about the materials or technique used, he said other characteristics can help authorities determine the provenance of the explosive.

“They’ll check for fingerprints and DNA and other trace particles,” said Chipman. “Sometimes with mail bombs or bombs packaged to look like they went through the mail, the package itself can hold evidence.”

Things like adhesives can also lend clues, said Chipman. He recalled a foiled bombing attempt in which investigators were able to collect samples from a suspect’s house and match them to particles stuck to the tape of the package, including hair from the suspect’s dog.

It’s not yet clear if the devices recovered this week will contain that sort of calling card, or whether the investigation will end up supporting claims that this was indeed a deliberate act of political terror against liberal political figures. Whatever authorities uncover, the plot is deeply concerning, said Chipman.

“This is an attack on our country and key components of it, whoever the individual targets are,” he said. “We need to come together and we need to support law enforcement to put this terror to an end.”