A Maryland man has been charged with the murder of his adopted 3-year-old son, Montgomery County police said Tuesday.

Brian Patrick O'Callaghan, 36, of Damascus has been charged with first degree murder and child abuse.

In court, O'Callaghan's lawyer said the suspect worked for the National Security Agency as chief of its Korea division; the boy had been adopted from Korea in October.

Police say O'Callaghan told investigators he was caring for 3-year-old Hyunsu for two days while his mother was away, adding he hadn't bonded much with his new son. O'Callaghan said he helped give Hyunsu a shower Jan. 31, during which he said the 3-year-old had slipped in the bathtub, falling backward and hitting his shoulder.

O'Callaghan told police the next afternoon, Hyunsu was unresponsive following a nap and had mucus coming from his nose. O'Callaghan said he took Hyusnu to a Germantown emergency room several hours later, where he was deemed to be in critical condition, possibly brain dead.

Hyunsu was pronounced dead two days later. Investigators say he had impact trauma on his body, as well as internal bleeding.

O'Callaghan was arrested Feb. 16 and is being held without bond.

At his hearing Tuesday, O'Callaghan's attorney also said O'Callaghan was a Marine veteran who had been involved in the rescue of Army POW Jessica Lynch. O'Callaghan served in the Marine Corps from 1997 through 2004 as sergeant.

According to his service record, O'Callaghan was deployed in support of Operation Iraqi Freedom for nine months in 2003 and served in Al-Wasit Province, An Nasiriyah and Al Kut. During the An Nasiriyah deployment, O'Callaghan worked with the Civil Affairs Group -- he was tasked with keeping civilians away from battle.

His awards include: Navy and Marine Corps Achievement Medal with Combat "V," Combat Action Ribbon, Navy Unit Commendation, Selected Marine Corps Reserve Medal, National Defense Service Medal, Kosovo Campaign Medal with 1 star, Iraq Campaign Medal with 2 stars, Global War on Terrorism Service Medal, Sea Service Deployment Ribbon with 1 star and Armed Forces Reserve Medal.

An obituary posted on the web site of the Frederick News-Post gave the child's full name as Madoc Hyeonsu O'Callaghan and said he was born in South Korea. He was described in the obituary as a "smiling, content, and loving son and brother.''



"He loved his dogs, his big brother Aidan, and anything his parents made for him to eat. He wasn't dealt the simplest hand in life, but he found something to love in it every day,'' the obituary said.

The Associated Press contributed to this report.