The Grand Blanc Township Police Department on Friday released body-worn camera footage and provided a timeline of the deadly shooting and fire at a Michigan church last weekend. 

The attack happened around 10:25 a.m. on Sept. 28, when police say Thomas Jacob Sanford, 40, of Burton, Michigan, drove his truck into the Church of Jesus Christ of Latter-day Saints on McCandlish Road in Grand Blanc Township, exited his vehicle, and fired "several rounds" from an assault rifle at hundreds of churchgoers before setting fire to the church. 

Four people were killed in the attack, and eight others were injured in what the FBI has called "an act of targeted violence."

On Friday, Grand Blanc police chief William Renye provided a timeline of law enforcement's response to the shooting. 

Renye said the first call to 911 came in at 10:25:23 a.m., when a victim reported that they had been shot in the abdomen. Dispatch then put a call out for response 16 seconds later. 

A Michigan DNR conservation officer was the first on the scene at 10:27:46 a.m. and encountered the suspect in the northwest corner of the church's parking lot. A Grand Blanc officer arrived at the church one minute, eight seconds later. 

In the body-camera footage, officers can be heard repeatedly telling the shooter to drop his gun. At the start of the video, two shots can be heard, which Renye said are believed to have been fired by the DNR officer. 

Renye said Sanford refused to drop his gun, at which time you hear eight shots being fired from the Grand Blanc Township officer. 

A member of the congregation with a handgun is also seen in the video, running in the direction of the shooter. That person did not fire a shot. 

Per state policy, the Michigan State Police is handling the investigation of the officer-involved shooting. Investigators will turn over their findings to the prosecutor. 

Both officers have been placed on paid administrative leave pending the outcome of MSP's investigation.  

"We will never forget this incident, but I promise that we will not let this define Grand Blanc," Reyne said Friday. 

CBS News confirmed that the shooter served in the U.S. Marines from 2004 to 2008. Sanford was an Iraq war veteran who deployed for several months during 2007 and 2008, according to service records provided by the Pentagon. 

Kris Johns, a Burton City Council candidate, told CBS News that he met the shooter at his home in the week leading up to the shooting while campaigning. Johns said Sanford had a dislike of the Latter-day Saints church, saying Sanford told him that the church's followers "believe they're above Jesus."   

The FBI is leading the case and has more than 100 personnel in Michigan and across the bureau collaborating with the Grand Blanc Township police and fire departments, the Genesee County Sheriff's Office, Michigan State Police, the Bureau of Alcohol, Tobacco, Firearms and Explosives and the U.S. Attorney's Office.

Earlier this week, Dr. Michael Danic, medical chief of staff at Henry Ford Genesys, said his hospital treated eight people injured in the attack, with the victims ranging in age from 6 to 78 years old. 

Danic said that five of the eight patients sustained gunshot wounds, while three others received treatment for smoke inhalation.