What is meant by opening archives

I was reading the site crime library and I noticed this phrase used several times.

For instance when they talked about the Lizzie Borden case they said they’d have till wait till like 2015 till the lawyers archives are opened

They also said something similar about the Sybil case. Whether or not it was a fraud.

They said whether or not Sybil was a multiple personality should be known in 2005 when the Dr Wilbur’s archives are opened.

I guess the question is, who closes them and who opens them. It can’t be a legal entity? I can see Dr Wibur wanting any records sealed as long as Sybil (now known to be Shirley Ann Mason) was alive. But they’re all dead as is everyone in the Lizzie Borden case. So what’s the point of keeping anything in an archive?

I hate to bump up an old thread but I was looking at some information on Sybil

Anyway since no one ever replied I thought I’d just bump this up rather than ask it again.

Anyone know what ever became of these archives?