CHICAGO (CBS) — Hundreds of people filled Federal Plaza on Sunday, calling for gun control reform.

At the ceremony, an activist read out many names of those who lost their lives to gunfire.

People held up flowers and signs remembering those who were killed in Chicago, as well as in last weekend’s mass shootings in Ohio and Texas.

A week ago Saturday, a gunman opened fire at a Walmart in El Paso. By Monday, a total of 22 people had died.

The suspected gunman, 21-year-old Patrick Crusius, has been booked on capital murder charges and is being held without bond, according to the El Paso County District Attorney’s Office.

In a racist manifesto Crusius allegedly wrote, he expressed support for the Christchurch, New Zealand mosque shooter and denounced the increasing Hispanic population in Texas.

The Dayton, Ohio shooting left nine people dead early a week ago Sunday. Authorities said Connor Betts, 24, opened fire outside a crowded bar in the city’s Oregon District. Betts was wearing a mask and body armor, and was armed with a .223-caliber rifle, local police said.

Among the victims in the Dayton shooting was Betts’ younger sister. Betts was later shot dead by police.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. CBS News and The Associated Press contributed to this report.)