A defense lawyer for Nathan Zuccherato and Michael Roberto, each charged with first-degree murder, attempted to discredit "Mr. Big" testimony from a gang member.

Video of a "Mr. Big" undercover sting operation – a type of operation which features an undercover police officer posing as a criminal to coax a confession from a suspect -- continued to be shown to a Calgary courtroom Tuesday.

Zuccherato and Roberto are charged with first-degree murder in the shooting deaths of Aaron Bendle, Sanjeev Mann and bystander Keni Su’a in a rival gang revenge plot on New Year’s Day 2009 at southeast Calgary's Bolsa Restaurant.

The three-hour long video is being played in place of testimony from a witness called John Doe, whose real name is being withheld by a court order. Doe refused to testify last week and was placed in contempt of court by Judge Earl Wilson.

In the video the jury saw admitted Fresh Off the Boat (FOB) gang member John Doe telling an undercover police officer posing as a crime boss about his involvement in the kidnapping of Aaron Bendle the night before the shootings.

Bendle was kidnapped and used as bait to lure Mann, a member of the rival gang FOB Killers (FK).

In cross-examination, defence lawyer Alain Hepner worked to highlight inconsistencies between John Doe’s story and other witness accounts.

When recalling the night of the kidnapping, John Doe said he worked with "Nat and Eric."

The Crown is attempting to tie the names to the defendants. The problem is linking the name Eric to Michael Roberto, whose middle name is Joseph.

Judge Wilson is expected to address Doe's contempt of court charge Friday.