EL PASO (KRON) — A gunman armed with a rifle opened fire in an El Paso shopping area packed with as many as 3,000 people during the busy back-to-school season, leaving 20 dead and more than two dozen injured, police said.

FBI and police held a press conference Sunday afternoon in El Paso to give updates on the shooting.

The gunman was on foot and approached by the El Paso Police Department and Texas Department of Public Safety. He surrendered to officers close to the scene and was immediately taken into custody.

The suspect has been charged for capital murder, set with no bond.

Whether the suspect was associated with a vehicle or not is unknown at this time.

Officials said they are hoping to put the investigation together to figure out if the gunman was associated with a group or individuals that were planning any other attacks.

“At this time we have confidence that there are no more,” officials said. “We’re looking extensively through interviews, people he has known, acquaintances. We’re conducting interviews in the Dallas area and San Antonio. He does not have any contacts here in El Paso.”

Police said some victims were in the parking lot when they were shot, but majority of the victims were in the Walmart store.

The Crime Services Unit has deployed over 18 victims specialists to assist the victims and families as well as witnesses.

The 18 individuals have been assigned to the Family Assistance Center at the MacArthur Elementary-Intermediate School.

Authorities say their plan is to have those victims specialists assigned to every family so that they can help get them through this tragedy.

FBI headquarters has agents, analysts and professional staff working on the investigation including the Strategic Intelligence Operations Center.

FBI Dallas and San Antonio is also involved.

Members of the Hate Crimes Domestic Terrorism Fusion cell are working on the investigation as well.

Three search warrants were served in the Dallas area this morning where agents collected several pieces of evidence from each location.

Forensics processing and review of the items has begun.

Authorities said they want to ensure the investigation evaluates all possible investigative tools as well as federal and state charges.

Officials ask if you have any photos or videos from the incident, to send them to the FBI website: FBI.gov/elpasoshooting

No further information has been made available.