[JURIST] US Army Sgt. John Hatley [JURIST news archive] entered a plea of not guilty to murder charges at his court-martial on Monday for the killing of four unarmed Iraqi prisoners [NYT report] in 2007. Hatley, along with Sgt. Michael Leahy, Jr. and Sgt. 1st Class John Mayo, was charged [JURIST report] in September with premeditated murder, conspiracy, and obstruction of justice. Hatley also faces murder charges for a separate killing of a prisoner during early January 2007. The trial began Monday at a US military base in Germany and will last all week with a verdict expected Friday [DW report]. If convicted, Hatley could face life in prison.

Last month, Mayo was convicted and sentenced [JURIST report] to 35 years in prison on charges of premeditated murder and conspiracy to commit premeditated murder after he pleaded guilty at his court-martial proceedings. He has also agreed to testify against Hatley [AP report]. Leahy was convicted [JURIST report] in February and sentenced to life in prison with the possibility of parole. Staff Sgt. Jess Cunningham, originally an alleged co-conspirator against whom charges were dropped, testified against Leahy [JURIST report] at his trial. Fellow unit members Spc. Belmor Ramon and Spc. Steven Ribordy pleaded guilty last year to conspiracy and accessory to murder [JURIST reports], respectively, in connection with the incident.