Updated

The family of an Oakland artist who was shot while working on an anti-violence mural has filed a claim against the U.S. Immigration and Customs Enforcement agency, saying it is partly responsible for the shooting because it was committed with an agent's stolen gun.

The family of Antonio Ramos announced the step toward a federal lawsuit Thursday, The San Francisco Chronicle reported.

Ramos was shot and killed Sept. 29 with a weapon that was stolen Sept. 13 in San Francisco from a car being used by an ICE agent. Marquise Holloway, of Oakland, was charged with murder in Ramos' death. Police say the shooting stemmed from an argument after Holloway eyed Ramos' camera equipment to steal.

"Despite ICE's knowledge and awareness of the problem and despite recommendations by other government agencies for corrective action, ICE agents continue to have their unsecured firearms stolen at alarming rates," said Frank Pitre, the attorney for Ramos's family.

Pitre said the agent failed to follow proper policies to stop the weapon from being stolen, such as keeping it in a bag or securing the weapon.

ICE officials didn't respond to a request for comment.

Ramos' death came just months after Kate Steinle, 32, was shot to death in July along the San Francisco waterfront with a gun stolen from a U.S. Bureau of Land Management ranger.

Steinle's family, also represented by Pitre, filed a wrongful-death lawsuit last month seeking damages from federal officials, the city of San Francisco and former Sheriff Ross Mirkarimi.

As a result of the high-profile deaths connected to stolen weapons, elected officials in Oakland and San Francisco have proposed new requirements for storing firearms in vehicles.