"Officer Harrison was a part-time Alamo police officer working his first shift with the department last night," Ammons said.
Officials have not released any details about what led to the deadly shooting.
In 2018, Harrison worked for the Oconee Drug Task Force. Previously, Harrison worked as an emergency dispatcher in his hometown, served as a firefighter in Savannah, and was employed by the campus police department at Middle Georgia State University.
Lisa Milks said her son-in-law dedicated his life to public service.
"He was super nice to everybody, give you the shirt off his back no matter what. He was always professional," Milks told WXIA-TV.
Harrison left behind a wife, who he would have celebrated two years of marriage in November. He also leaves behind their baby named Brody.
Georgia Gov. Brian Kemp offered his condolences to Harrison's family and the Alamo Police Department.
"Early this morning, one of our law enforcement officials in Middle Georgia was killed in the line of duty," Kemp said on Saturday. "Our thoughts and prayers are with this officer's family, friends, and colleagues at the Alamo Police Department. May God continue to be with all who protect and serve."
The Georgia Department of Public Safety said, "We are deeply saddened to hear of the loss of Alamo Police Department's Officer killed in the line of duty early this morning. We send our thoughts and prayers to the Officer's family, blood and blue."
The McRae-Helena Police Department wrote, "Officer Dylan Harrison formerly of Cochran PD, and Middle Georgia State University Was ambushed and killed in Alamo last night. He leaves behind a wife and 6 month old. I pray the suspect is caught soon and justice is quick."
Telfair County Sheriff Sim Davidson said, "Our sincerest thoughts, prayers, and condolences to the family, friends, and co-workers of Officer Dylan Harrison who was killed in the line of duty last night in Alamo. We are sincerely grateful for his service. Rest In Peace sir."
A manhunt is now underway for the man the GBI believes shot and killed Harrison. The GBI issued a blue alert for 43-year-old Damien Anthony Ferguson, who also goes by the name of "Luke Ferguson."
The Atlanta Journal-Constitution reported, "Ferguson spent more than seven years in prison after being convicted of charges including theft by taking and aggravated assault on an officer in Wheeler County. He was released from the Coffee Correctional Facility in August 2006, Georgia Department of Corrections records show."
"Anyone with information on the whereabouts of Ferguson or with any information you think may be pertinent to this investigation should contact us," Ammons said.
GBI has offered a $17,500 reward for any information leading to Ferguson's arrest. Tips can be reported online or called in at 1-800-597-TIPS.
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