"have a broadcast out on"
It's police jargon.
Jargon - special words or expressions that are used by a particular profession or group and are difficult for others to understand
Broadcast out = a message has been sent via police radio to everyone on patrol to look for Carly Beck's vehicle. It would be known as an All-points bulletin or BOLO/BOL (be on the look-out) today.
An all-points bulletin (APB) is a broadcast issued from any American or Canadian law enforcement agency to its personnel, or to other law enforcement agencies. It typically contains information about a wanted suspect who is to be arrested or a person of interest, for whom law enforcement officers are to look.
An all-points bulletin can also be known as a BOLO or BOL, which stands for "be on (the) look-out".
Carly Beck has no known employer