President Obama is calling on Congress to revisit gun control legislation in the aftermath of Monday’s shooting rampage at a naval base in Washington, D.C., that left 13 people dead, including the gunman. Speaking to the Spanish-language television network Telemundo, Obama said the spate of mass shootings in the United States should force lawmakers to take action.

President Obama: “The fact that — we do not have a firm enough background-check system — is something that makes us more vulnerable to these kinds of mass shootings. And, you know, I do get concerned that this becomes a ritual that we go through every three, four months, where we have these horrific mass shootings. And yet we’re not willing to take some basic actions.”

The last major gun control effort failed in April when a handful of Senate Democrats joined with Republicans to defeat a watered-down measure on expanding background checks. According to The Atlantic magazine, if the rate of mass shootings continues as it has since President Obama took office, there could be 14 before the end of his second term.

Aaron Alexis Bought Shotgun Despite Arrests, Mental Issues

The alleged D.C. shooter, Aaron Alexis, bought a shotgun used in the rampage just this past Sunday. Officials in Virginia say he passed both state and federal background checks, despite at least two gun arrests and being under treatment for psychiatric problems. Just last month, Rhode Island police alerted the Navy after Alexis told them he was hearing voices and was being followed by three people harassing him with a microwave machine.