This verse has been completely restructured in the Good News Translation. For a rather literal rendering of the Greek see Revised Standard Version.

With all boldness, in this type of context, is sometimes rendered as “without holding back anything” or “with complete openness.”

In a corner is a good Greek expression, and not a Semitism. In many languages one cannot refer to an event by an expression such as this thing. Therefore, one may say “what has happened did not take place in a corner.” However, the phrase in a corner may be relatively meaningless in some languages. The closest equivalent would therefore be “in some dark place” or “in some unknown place”—for example, “what happened did not take place in an unknown location.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .