VILSECK, Germany â A military court convicted a second U.S. soldier of murder in the execution-style slayings of four bound and blindfolded Iraqi detainees in 2007 after the soldier pleaded guilty at his court-martial Monday. Wearing his dress uniform and speaking crispy and confidently, Sgt. 1st Class Joseph Mayo of Fort Bragg, N.C., pleaded guilty to charges of premeditated murder and conspiracy to commit premeditated murder at the proceeding at the U.S. Army's Rose Barracks in southern Germany. He pleaded not guilty to a charge of obstruction of justice in the incident, which occurred while he was deployed to Iraq. Military prosecutors dropped that charge. The 27-year-old will be sentenced later Monday and faces the possibility of life in prison, along with a reduction in rank to private, forfeiture of all pay and a dishonorable discharge. Col. Jeffrey Nance, the judge overseeing the proceedings, told Mayo that he "entered into an agreement to commit premeditated murder" that saw the four Iraqi men shot in the head by the side of a canal in Baghdad between March and April 2007. In February a military court convicted Sgt. Michael Leahy, 28, of Lockport, Ill., to life in prison with the possibility of parole after he admitted to the execution-style killing of one of the detainees and shooting another. He was acquitted of murder over a separate incident in Baghdad in January 2007. According to testimony at previous courts-martial, at least four Iraqis were taken into custody in spring 2007 after a shootout with a patrol. The Iraqis were taken to the U.S. unit's operating base in Baghdad for questioning and processing, although there was not enough evidence to hold them for attacking the unit. Later that night patrol members took the Iraqis to a remote area and shot them in retribution for the attacks on the unit, according to testimony. Story continues below Mayo, Leahy and Master Sgt. John Hatley, 40, are accused of pulling the trigger. "Hatley stated that if we took (the) individuals to detention they'd be released in a matter of days," Mayo told the court. "He said we should take care of them. I agreed." All were with the 1st Battalion, 18th Infantry Regiment, 2nd Brigade, 1st Infantry Division. The unit is now part of the Germany-based 172nd Infantry Brigade. Hatley's court-martial on charges of premeditated murder, conspiracy to commit premeditated murder and obstruction of justice is scheduled for April. The Army has also not released a hometown for Hatley. Hatley also faces murder charges from the separate incident in Baghdad. Two soldiers _ Spc. Steven Ribordy, 26, of Salina, Kansas, and Spc. Belmor Ramos, 24, of Clearfield, Utah _ pleaded guilty to conspiracy to commit premeditated murder and were sentenced to prison last year. Staff Sgt. Jess Cunningham, 29, of Bakersfield, California, and Sgt. Charles Quigley, 28, of Providence, Rhode Island, had charges of conspiracy to commit premeditated murder dropped this year. It is unclear whether they will testify in the upcoming courts-martial.