A former Fairfax County police officer has been charged with multiple counts in the death of his 6-month-old daughter in Maryland last year, authorities announced Tuesday.

Jason Colley, 38, of Monrovia, Md., turned himself in to police in Frederick County on Tuesday after a Maryland judge signed his indictment in the death of Harper Colley, who died in October.

The Maryland state’s attorney for Frederick County said in a news release that Harper suffered her initial injuries Sept. 19, sparking an investigation.

Andrew Jezic, an attorney for Colley, said his client plans to plead not guilty and that they will “vociferously assert his innocence.”

Authorities said the child suffered head trauma. Jason Colley has been charged with child abuse in the first degree resulting in death, child abuse in the first degree resulting in severe physical injury and felony assault in the first degree.

“The charges Colley faces are abhorrent,” Fairfax County Police Chief Edwin C. Roessler Jr. said in a statement. “This afternoon I served Colley notice of separation from employment in accordance with Fairfax County Personnel Regulations and the Code of Virginia.”

Fairfax police said Colley had been with the department for about 10 years and was stationed in Reston. He worked as a patrol officer. Officials said department rules prevented them from discussing whether he had previous disciplinary issues.

Fairfax police said they were notified April 20 that Colley was a suspect in the case. When he reported for his next shift, he was relieved of his duties and all law enforcement powers, police said.

Jezic said Colley has been married for over a decade and that Harper was the couple’s only child. They were heartbroken by her death, he said.

“This child was their greatest dream,” Jezic said. “Their greatest joy.”

He said that his client was caring for his daughter in the hours before she was injured and that nothing seemed abnormal. Jezic said that he did not know what happened to the girl and that they were awaiting more details from prosecutors.

“He’s been a police officer in good standing,” Jezic said. “He’s had no discipline issues on the job. He’s someone that appears to be widely supported by his colleagues on the force, and he has no record. He has been married to a scientist for 12 years.”

Jezic said Colley’s wife and a neighbor testified on his behalf at a bond hearing in Frederick County court on Tuesday. Colley was granted a $100,000 bond, and Jezic said he had posted it by Tuesday evening.

No other court dates have been set.

Dan Morse contributed to this report.