The families of two Dallas officers shot last year inside a Home Depot have filed a lawsuit against the alleged killer, the home-improvement store, a Dallas-based security company and two people who worked security that day.

The April 24, 2018, shooting at the store near Forest Lane and U.S. Highway 75 left officer Rogelio Santander Jr. dead and Crystal Almeida seriously wounded.

The two families’ lawsuit, filed Friday in Dallas County, alleges negligence by Home Depot. At the center of the suit is the allegation that security officers at the retailer “failed to perform an adequate search” and properly detain shoplifting suspect Armando Luis Juarez.

When Almeida and Santander showed up to the Home Depot, the officers “were under the belief that Juarez had been appropriately detained, searched, and pat-down for weapons,” the lawsuit said.

The lawsuit said off-duty officer Chris Seward initially searched Juarez and found a can of mace, but failed to complete the search.

Police said Juarez had a gun in his pocket. After Santander and Almeida arrived to take him into custody, Juarez allegedly drew his gun and shot them and loss-prevention officer Scott Painter. The lawsuit called the incident a “preventable shooting.”

According to the lawsuit, when a business detains a suspected criminal and calls in the police, “it is a standard industry practice” for security to search and disarm a suspect before the suspect is detained and before the police arrive.”

“It is also a standard practice to handcuff a detained individual until they are released,” the lawsuit said. Juarez was unrestrained, according to the suit.

The lawsuit states Home Depot hired Allied Universal Security Services and off-duty police officers after the store saw increased criminal activity. But the suit also faulted Home Depot for not allowing security to carry firearms.

Margaret Watters Smith, a spokeswoman for Home Depot, said “our hearts go out to the officers and their families but we have not yet seen the suit.”

A woman who answered the phones for Allied Universal Security Services declined to comment and deferred questions to its Dallas headquarters.

The lawsuit also names as individual defendants Painter, Seward and Allied Security officer Elijah Lateef. The three could not be reached for comment.

Santander’s father, who is also named Rogelio, did not respond to a call seeking comment. The Dallas Police Department also did not respond to requests for comment.

Juarez is also named a defendant in the suit. Authorities took him into custody after a five-hour manhunt, and he remains in jail on multiple charges, including capital murder.

Prosecutors are seeking the death penalty.

Twitter: @cassandrajar