The state of Colorado has very firm secrecy laws to protect minors in the juvenile system, and to protect innocent victims of crimes like incest, in which the very connection to the criminal would victimize them further. Because the state has no "witness protection" plan, sealing a case may have been also used to ensure witness safety from time to time. If that happened, the whole case would be sealed, not just the case against a co-conspirator. However, in recent years, the legislature has mandated that nearly anyone who has been exhonerated or has completed the full conditions of sentencing can apply to have their case sealed. They must prove that it is neccessary, but I'm not familiar with the process. The Denver Post filed one lawsuit, to open one case, to flesh out a tabloid story. The banner picture and caption featured a murder in which four boys were charged and convicted. One was barely of legal age. Two were charged as adults, while minors. The fourth was processed through the juvenile system.
In that case, it has already been ruled that the adult trials can be unsealed after the child becomes an adult. By state law, the child's process is sealed forever. The Denver Post doesn't seem to like that.
There is an entirely different process in Colorado under which someone who has been convicted of a listed crime and has satisfied all of their sentencing and is in good standing otherwise can apply for sealing of that conviction, primarily to protect them in background checks, etc. I'm not familiar with how that sealing works. Again, the Denver Post doesn't seem to like that very much.
On the civil side, for many years nearly every adoption of a child from the state orphanage system was sealed, then destroyed after a period of time.
I'm not aware of the Denver Post ever objecting to that, but I could be wrong.
IMO