The federal murder-for-hire trial against Chris Latham and Wendy Moore has been postponed until at least Thursday due to winter weather.

Latham, 51, and Moore, 37, are accused in an alleged murder-for-hire scheme that authorities said targeted Latham's estranged wife, Nancy, in April 2013. Their trial began Monday in downtown Charleston.

On Tuesday, U.S. District Judge Richard Gergel said he was canceling court Wednesday because of travel safety concerns for the jurors during the winter storm expected to hit the area Wednesday. Gergel said he will make a decision about Thursday's proceedings later.

Aaron Russell Wilkinson, 40, a key witness in the case took the stand on Tuesday afternoon. He pleaded guilty last month to aiding and abetting murder-for-hire and agreed to testify for the prosecution. Wilkinson was originally charged along with Latham; Moore; Moore's ex-husband, Samuel Yenawine, 38, of Louisville, Ky.; and Yenawine's girlfriend, Rachel Palmer.

Yenawine committed suicide in June following his arrest while jailed at the Georgetown County Detention Center. Palmer is not standing trial with Moore and Latham. It's unclear if she has pleaded to any charges.

Wearing shackles and jail garb, Wilkinson, testified in a soft-spoken tone for about three hours.

He spoke of his and Yenawine's involvement in the alleged scheme and how they ended up in South Carolina on a mission to kill Nancy Latham. He told the jury he was initially believed he was traveling with Yenawine to buy drugs in Tennessee. He said he later found out about the alleged murder-for-hire plot.

When asked by prosecutors why he stuck around once he knew they were in South Carolina to kill someone, he said it was out of fear.

"It's not like Sammy was a soccer dad down the street," Wilkinson said. Yenawine had killed someone and gotten away with it, he said.

Defense attorneys of Moore and Latham have questioned Wilkinson's credibility, calling him a liar and heroin addict, but during his testimony, Wilkinson said he is now clean.

He is the one who first informed police about the alleged plot after being arrested on Charleston's East Side and charged with driving under suspension. He had been pulled over and later told investigators he was in the area trying to buy heroin, authorities said.

His testimony will continue either Thursday or Friday, depending on whether the judge postpones the trial again.

The trial is expected to last two weeks.

Reach Natalie Caula Hauff at 937-5594 or Twitter.com/ncaula.