Two New York police officers were shot and killed on Saturday in Brooklyn by Ismaaiyl Brinsley, who is believed to have traveled from the Baltimore County area that day after shooting his ex-gilfriend around 5:45 a.m. Baltimore County Police warned the NYPD that Brinsley’s cellphone had been traced to Brooklyn, but not in time to prevent the shootings.

The Baltimore County Police and the New York Police Department are inconsistent in their reporting about the exact time that Baltimore alerted New York to the suspect’s potential presence in Brooklyn. This discrepancy suggests that the use of outdated communication technology—fax machines and teleprinters—in these exhanges may be significant.

New York City Police Commissioner Bill Bratton said in a press conference Saturday that the NYPD received a faxed wanted poster from Baltimore County Police at 2:45 p.m. Baltimore County Police said in a statement Saturday that they called the 70th Precinct in New York at 2:10 p.m. and also faxed the wanted poster at that time. The officers who were killed were from the 84th Precinct, but had been dispatched to the area the 79th precinct patrols to assist in a community violence reduction initiative.

The Baltimore County police also said that at 2:50 p.m., right as the two police officers were being murdered, they sent the information from the wanted posted to the NYPD’s “real-time crime center—essentially, a data warehouse” in the form of a teletype. Teletypes, also known as teleprinters, are typewriters that can independently type out messages sent over non-switched telephone circuits, the public telephone network, radio, or microwave links. They were popular for remote communication before fax machines and the rise of the Internet, and their use has declined since the 1980s. For example, the Teletype Corp. made its last teleprinter unit, the Teletype Dataspeed 40, which included a CRT monitor and a high-speed printer terminal, in 1979.

Police departments are *faxing* each other potentially life-saving information, in 2014 pic.twitter.com/5hpqNsy7qY — Christopher Ingraham (@_cingraham) December 21, 2014

The Twitterverse quickly started discussing the old-skool technology and speculating about whether its use could have slowed communications.

Baltimore County Police did use analysis of Instagram posts to trace Brinsley’s phone to Brooklyn, but at that point the high-tech sleuthing gave way to retro communication. Fax machines are still frequently used by businesses and agencies instead of email to send sensitive communications, but they aren’t necessarily more secure. Depending on the type of line they connect to and whether the data being sent is encrypted, they may be secure or vulnerable to eavesdropping on the line. Teleprinters may offer some security simply because they are obsolete, but their use in law enforcement seems to come from tradition. A Baltimore County Police Liaison told Slate that the department uses teleprinters because they’re “very reliable.”

