There's probably a simple explanation for this, but I've wondered why LAPD units and dispatchers, when they say Code 4, which means no further assistance needed, will oftentimes add "sufficient units at the scene." It just sounds redundant and a slight waste of busy airtime. TIA
That's a reasonable question, with a fairly easy answer. There are a number of reasons for an ofcr to broadcast a "Code 4," and his/her giving the reason for it will often affect what the other responding units will do, and it alerts the RTO as to what the situation is at the scene and what may be expected next.
Your example of "Code 4, sufficient units" strongly implies that that the incident isn't over yet, and probably that the suspect, if any, isn't in custody, but there are sufficient officers there to handle it. It may be a call localized to a specific place, like a home, or it may involve a perimeter, but it's still conveying that they've got enough officers there to handle it, and other responding units can go back to whatever they were doing, but still remain aware that it isn't quite over yet.
"Code 4, suspect in custody" lets everyone know that the situation is essentially stable and will be wrapping up soon, with not much likelihood that it's going to go sideways.
There is also a "
Code 4 Adam" which means there are sufficient units at the scene, but the suspect is still outstanding. In this case, other responding units will continue to the area (but not the scene) of the call to look for the suspect, of whom the handling officer should be broadcasting a description and the crime for which he's wanted.
There are other self-explanatory Code 4 subtypes, such as "Code 4, no 211 (or 'no 459,' 'no shooting,' or 'suspects and victims GOA' ). Those all pretty much mean that there's no apparent crime, so again everybody can go back to whatever they were doing before.
In all those cases, a plain "Code 4" with no explanation would leave other responding officers and the RTO wondering whether or not to expect to hear more details that they need to be aware of.