(CNN) While the announcement on Sunday of the death of ISIS leader Abu Bakr al-Baghdadi has been praised among a bipartisan group of elected US leaders, current and former law enforcement officials say the possible threat to the US homeland by ISIS sympathizers persists.
Two senior US law enforcement officials tell CNN that agencies and police departments around the country remain on guard for any potential coordinated or lone-wolf attacks that could occur by individuals seeking to retaliate against the death of Baghdadi, who died Saturday evening during a raid in Syria by US special operations forces.
The officials noted that although authorities remain on alert, there is currently no known specific or credible threat to public safety.
Since the major rise of ISIS in 2014, federal law enforcement has dedicated significant resources to investigating sympathizers of the group and stopping plots inside the United States. Earlier this month, an FBI spokesperson told CNN that of the approximately 5,000 open international terrorism cases being investigated by the bureau, about 1,000 are on individuals associated with ISIS.
Recent cases of thwarted plots include the arrest of Everitt Jameson, a 27-year-old former US Marine who was sentenced to 15 years in prison for providing material support to ISIS and attempting to conduct a Christmas holiday terrorist attack in San Francisco in 2017.
Another case involved the arrest of Vicente Solano, a 53-year-old ISIS sympathizer who was sentenced to 17 years in federal prison after the FBI learned of his desire to bomb a Florida shopping mall.
The concern by law enforcement about potential attacks following the death Baghdadi is similar to those that resulted in the wake of the killing of Al Qeada leader Osama bin Laden. Following his death, the Department of Homeland Security issued a warning to law enforcement to be on alert, although no domestic attacks materialized.
According to experts, the death of Baghdadi will require additional vigilance on the part of law enforcement to identify new potential threats, while also ensuring they have complete visibility on known and suspected bad actors.
"The FBI will be increasing surveillance on individuals on their radar as ISIS followers, and will likely increase attention to social media platforms," said Lisa Monaco, a former career national security prosecutor who also served as homeland security adviser under President Barack Obama.
Although President Donald Trump has previously declared the defeat of ISIS, that view is not universally held among national security professionals.
"ISIS is not defeated," said Brett McGurk, the former US envoy for the anti-ISIS coalition, who resigned in December following Trump's decision to withdraw troops from Syria after announcing the terrorist group's demise.
This view of ISIS' lingering threat is shared by other experts who note that the group's near certain territorial defeat does not mean its violent ideology will be equally eliminated. Current and former government officials tell CNN the terrorist group will continue to have the ability to inspire sympathizers around the globe to act with violence, regardless of its current status on the battlefield or the death of its leadership.
"The bottom line is this is a great day for the US national security community and the unrelenting focus of counterterrorism professionals," said Lisa Monaco. "But they also know that the ideology does not die with Baghdadi, and we have to remain vigilant."
Josh Campbell is a CNN law enforcement analyst and former FBI supervisory special agent.