By Jim Melwert

By Jim Melwert

NORRISTOWN, Pa. (CBS) — Former Montgomery County district attorney and commissioner Bruce Castor will be sworn in later today as Kathleen Kane’s replacement as Pennsylvania Attorney General.

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In a sweeping press conference that covered a variety of topics, Castor discussed the possibility of a criminal investigation into a key prosecution witness at Kane’s trial.

Political strategist Joshua Morrow, during his testimony at the Kathleen Kane trial, admitted he lied under oath in multiple appearances before the Grand Jury.

Morrow was given immunity to prevent him from pleading the 5th. That means his testimony or anything derived from his testimony cannot be used against him, but Bruce Castor says it doesn’t mean he can never be prosecuted.

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“If he can be proven to have committed perjury without using the testimony that he gave during the trial and using other evidence.”

According to testimony, Morrow gave consent to county detectives for certain text messages to be taken from his phone. It’s unclear if those messages would be covered by the immunity order, which is dated a week and half later.

Castor tells reporters he isn’t threatening Morrow, and he says he wonder if the Montgomery County DA’s office would have the authority to bind the AG’s office.

The Montgomery County DA’s office declined to comment.

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