CBC News has learned that the two men charged with first-degree murder in the fatal shooting of four RCMP officers in Mayerthorpe, Alta., are expected to plead guilty Monday to a lesser charge of manslaughter.

Shawn Hennessey and Dennis Cheeseman will appear in an Edmonton courtroom on Monday.

They will enter guilty pleas on manslaughter charges, according to family and police sources.

The defence lawyers are expected to ask the judge to sentence each man to a five-year jail term, while the Crown is expected to request a sentence in the range of 10 to 15 years. 

Hennessey and Cheeseman are accused of helping James Roszko kill the four RCMP officers at his Mayerthorpe farm in March 2005, even though police said neither man pulled the trigger or was even there when the officers were killed.

Roszko ambushed and gunned down the officers, and then killed himself.

Constables Brock Myrol, Peter Schiemann, Anthony Gordon and Leo Johnston all died that day, the single worst loss of life in RCMP history.

Hennessey and Cheeseman were scheduled go on trial for first-degree murder in April. 

They were both arrested in July 2007 and charged under Sec. 21 of the Criminal Code, entitled "Parties to Offences," which says that a person who helps another person commit a crime can be found guilty of the same crime.

Both men were ordered to stand trial after a preliminary hearing in June 2008. 

All the evidence presented at the preliminary hearing is covered by a publication ban and cannot be reported.

Both men are free on bail.

A family member of one of the slain officers told CBC News the victims' families plan to be in the Edmonton courtroom on Monday morning and will be arriving with an RCMP escort.