De Vignes, 29, was shot in the head on Friday Novemebr 9, at Upper St Barbs.
PC Silvester has been charged with De Vignes’ murder.
Yesterday, St Barbs resident Alister Welch testified before Chief Magistrate Sherman Mc Nicolls in the Port-of-Spain Eighth court.
During the cross-examination, Khan and Welch traded verbal blows in the presence of the magistrate. Khan raised his voice several times at Welch who fearlessly shouted back at the attorney.
Mc Nicolls did not intervene but, he did instruct Welch to answer the questions posed
to him. Welch, a body builder, spent ten minutes giving his evidence in chief.
The court was filled with St Barbs residents and the family and friends of De Vignes. PC Sylvester clad in a navy blue suit sat attentively in the dock and took in the proceedings. The matter was adjourned to today.