After two mass shootings over the weekend, the FBI is warning about high concern for copycats.
Agents are worried they could inspire another shooter to commit another similar crime.
"The attack in El Paso, Texas underscores the continued threat posed by domestic violent extremists and perpetrators of hate crimes," the FBI said in a statement.
Prosecutors said they will seek the death penalty for the 21-year-old suspected of fatally gunning down 22 people and injuring dozens of others at an El Paso Walmart Saturday.
"On behalf of the FBI, I offer sincere condolences to the victims, families, and communities affected by this weekend's violence, and we stand by them during this difficult time. We will bring the full resources of the FBI to bear in the pursuit of justice for the victims of these crimes." said FBI Director Christopher Wray.
The FBI will support state and local partners in Texas through investigative, intelligence and technical assistance.
"The FBI remains concerned that U.S.-based domestic violent extremists could become inspired by these and previous high-profile attacks to engage in similar acts of violence. The FBI asks the American public to report to law enforcement any suspicious activity that is observed either in person or online," the statement said, in part.
The latest news from around North Texas.
The El Paso investigation is being supported by the FBI's Domestic Terrorism-Hate Crime Fusion Cell, which was established in spring 2019.
The FBI is also providing assistance to the Dayton (Ohio) Police Department's investigation into the shooting in Dayton, through the Bureau's Cincinnati Field Office, with support from FBI Headquarters personnel.