The deranged perpetrator who ambushed and killed officers Rafael Ramos and Wenjian Liu on December 20, 2014 threatened and communicated via a social media Instagram account that he was going to kill police officers in retaliation to the police involved deaths in Ferguson, Mo and New York City. Unfortunately that information made it to New York too late.
On May 19th 2015 President Obama signed the blue alert law named The Rafael Ramos and Wenjian Liu National Blue Alert act of 2015.This law will require that the Justice Department create a notification system relating to assaults on police officers, officers who are missing in the line of duty, and credible threats against law enforcement. It is designed to provide instant nationwide "Blue Alerts" to warn about threats to police officers and help track down the suspects who carry them out. The system is modeled after Amber Alerts for abducted children and Silver Alerts for missing seniors. The Rafael Ramos and Wenjian Liu Blue alert law was easily passed with tremendous bipartisan support. It was so uncontroversial that it passed both the House and the Senate by voice vote.
Obama said in an Oval Office signing ceremony with the families of the slain officers: "They were serving their community with great honor and dedication and courage, and all of New York grieved and all of the nation grieved." It's important for us not only to honor their memory, it's also important for us to make sure that we do everything we can to help ensure the safety of our police officers when they're in the line of duty."