A New Brunswick man is facing a first-degree murder charge in the death of his baby boy after RCMP upgraded charges against him and his common-law wife.

Rodney Miller, 27, is charged with first-degree murder, and Sarah Russell, 19, has been charged with manslaughter and being an accessory after the fact in their baby's death.

The Moores Mills, N.B., couple appeared in St. Stephen provincial court on Tuesday, where the new charges were laid. Both were charged on Jan. 30 with concealing the body of a newborn.

There was a lot of tension in the St. Stephen courthouse as the couple was jeered by about a dozen angry spectators who showed up. Inside, the courtroom was packed full of onlookers for the hearing, and it was the first time that metal detectors had been used to scan people going in.

Tammy Connell had her grandson with her on Tuesday as she expressed the outrage many are feeling in the small New Brunswick community.

"This is my grandson. Can you imagine? He has the opportunity in the world to grow up and become whatever he wants to. We will guide him anyway he wants to go. But, can you imagine if somebody took him?" Connell said.

Four officers stood outside earlier as the couple entered the courthouse. Police were concerned that demonstrators horrified by the crime might disrupt the proceedings. Sheriff's deputies turned away four people carrying babies as they tried to enter the court.

"There's been some frustration and anger in the community.… So we thought it was probably prudent, rather be safe than sorry of the off-chance that someone decided to act out on their frustrations or anger," said RCMP Sgt. Greg MacAvoy.

RCMP have concluded that the baby boy was born between Jan. 5 and Jan. 22, 2009. They say the infant was killed and the body was hidden. Police have retrieved the body and are continuing their investigation.

Miller and Russell are being represented by different lawyers in the case. Both are undergoing 30-day psychiatric evaluations.

The next court appearance for the two is March 17.