Manhattan prosecutors seek new charges against ex-movie mogul Harvey Weinstein

The transcript discusses ongoing sexual assault allegations against Weinstein. Prosecutors are investigating new claims, despite no new charges being announced. After his conviction was overturned in April, they plan to present at least one victim's allegations to a grand jury. Weinstein is scheduled to return to court on July 19th.

What was the context of the prosecutors' actions mentioned in the text?

What happened to Weinstein's conviction in April?