A Vancouver Island RCMP officer has pleaded guilty to fabricating evidence to obstruct the course of justice by taking a paternity test on behalf of a fellow officer.

Const. Dereck Carter reported to a lab and took the court-ordered test in July last year on behalf of Greg Doncaster, who was then also a constable on the force. Doncaster had approached him after a woman with whom he'd had an affair took steps to recover child support.

Doncaster told Carter the paternity case would cost him his marriage, and Carter felt obliged to help his mentor on the RCMP's Regional Crime Unit.

But the plot was discovered by the child's mother. Last month, Doncaster pleaded guilty to fabricating evidence and received a six-month sentence to be served in the community.

Carter pleaded guilty to the same charge Tuesday in B.C. Supreme Court. The Crown has asked for the same sentence but the defence is asking for a discharge, meaning no criminal record. It is arguing that, of the two, Carter was less culpable and that he was pressured into a scheme that Doncaster orchestrated.

Carter remains on the force but is suspended without pay. Doncaster is no longer an RCMP officer.

