An East Baton Rouge Parish sheriff's deputy was justified in the fatal shooting of a man last year who earlier in the night killed his girlfriend in a frenzied attack that included shooting a high-school student who tried to help the woman, District Attorney Hillar Moore III said Tuesday. 

Terrell Walker, 48, shot April Peck inside a car on Essen Lane, then pushed her out into an intersection, according to officials and the report released Tuesday about the Nov. 27, 2016, incident.

"Oh my God, oh my God, I'm at the corner at Essen Lane, and, oh my God, I don't even know what this is," a passer-by said in a call to 911 that was included in the report. "Shots fired and I see somebody on the ground. ... He did a U-turn and is headed the opposite way and pushed her out of the car, oh my God. ... She is not moving."

When motorists stopped to help Peck — including a physician, a 17-year-old Central High School student training to be an EMT and the crew of a passing ambulance — Walker returned and attacked them, striking two of them and Peck with his car. He then exited the vehicle and began shooting at both the teenager and others nearby, the report says. Walker also chased and yelled threats against Emergency Medical Services personnel who drove onto the scene. 

"The guy was actually chasing me with the gun, saying that he was going to kill me for helping her," relayed one first responder in EMS radio traffic.

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Walker then drove from the scene, hitting the EMS ambulance as he fled, the report says. 

Both the high school student and Peck were transported to the hospital, where Peck died. The teenager survived his injuries. 

After identifying Peck as the victim of the initial shooting, sheriff's deputies developed Walker as a suspect, as they saw she had twice accused him of domestic assaults earlier in the month, Moore said. 

Just two weeks before the shooting, Walker was taken to the hospital for a psychiatric evaluation by police after allegedly hitting Peck but was released soon after. The next day, Peck told police Walker had choked her and stepped on her face; he was later arrested on domestic abuse battery. However, he soon posted bail, according to the report. Court records show Walker had two protective orders filed against him at some point. One of those was filed by Peck, 30, who had two children with Walker.

Speaking at a news conference Tuesday, Moore described Walker as having a "significant history of violence against women."

Detectives were able to then track Walker's location through his cellphone number, which they had on file from previous police reports. Moore said officials contacted his cellphone provider for the GPS coordinates, which soon showed Walker was in the area between North Mall Drive and Bluebonnet Boulevard. 

While searching the vicinity, Sheriff's Office detective Benjamin Friedman found Walker on foot on the Interstate 10 westbound entrance ramp. He called for back-up, which came from SWAT deputy Shawn Anderson. 

Neither Friedman nor Anderson had been identified by the Sheriff's Office before the report was released. 

The two deputies got out of their vehicles, asking Walker to stop walking — to no avail. Instead, he said, "I didn't do nothing, man," and ran across the interstate, the report says. 

Moore said the detective chased Walker across the interstate until Walker fell by a fence just off the eastbound exit ramp near Bluebonnet Boulevard. Moore said the detective showed restraint by not pulling his weapon, instead giving verbal commands to Walker to show his hands. Walker ignored those commands and remained lying on the ground, according to statements from the deputy. 

Moore said the detective realized, while standing in the pitch black of the night, he didn't have on his protective vest, so he began moving side to side to become a more difficult target but still did not pull his weapon. Soon after, the SWAT deputy joined the detective in his marked vehicle and exited armed with a rifle. 

"Detective 1 then saw a bright muzzle flash aimed at him and heard a gunshot. Detective 1 instinctively un-holstered his firearm and fired at Walker," the report says. Moore said the detective emptied his magazine by firing 11 rounds at Walker. The SWAT member also fired three rounds at Walker, the report says. 

Walker would eventually die of gunshot wounds fired by the detective, autopsy and State Police crime lab analysis determined. 

Investigators found one shell casing at the scene that matched Walker's weapon; however, they were never able to determine the path of that bullet, Moore said. A Smith and Wesson 9mm pistol was found on the ground by Walker, said Moore, who showed a picture snapped by deputies. 

"The incident was not recorded on any dash camera or body camera. Furthermore, there is no video of this incident known to law enforcement," the report says. State Police conducted the investigation into the officer-involved shooting, per protocol. 

According to his autopsy, Walker had a blood-alcohol concentration of 0.028, and concentrations of multiple drugs in his system, including methamphetamines and marijuana, as well as phencyclidine, which is found in PCP, hydrocodone, and amphetamine, found in Adderall. Walker's medical records show he had been diagnosed with schizophrenia and was known to have hallucinations and experience paranoia when off his medicines, Moore said.

"At the time of his death, Walker's mental illness combined with the mixture of narcotics in his system would have likely caused him to be restless, aggressive, psychotic and have an altered mental status," the report says. 

Moore said he determined the deadly force used by the two sheriff's deputies in this incident was justified as the two officers were placed in an "extremely dangerous situation" and feared for the life of another deputy or themselves, the report says. 

"The death of Terrell Walker was legally justified and no criminal responsibility can be found for the deputy involved as he was legally exercising his rights of self-defense and defense-of-others," the report says. "(The shooting happened) in the course and scope of his employment as a law enforcement officer."

Moore said he is aware his review of this shooting and his determination of culpability took more than a year to release, which he said has been the outcome of a constantly growing workload. He said since last November, his office has been tasked with reviewing and analyzing three other officer-involved shootings and an unprecedented number of homicides, more than 100. 

"It's taken some time," Moore said. "These reports have taken significant effort not only to write, but to review."

Moore has not made any determinations in those three other officer-involved shootings. He said he expects to release in February his findings in the March 18 incident where sheriff's Deputy Shawn Anderson — also involved in the Walker case — and Brandon Wiley were both killed in a scuffle after Anderson and a detective tried to question Wiley in a rape investigation at a O'Neal Lane hair salon.

Then on June 13, Baton Rouge police officer Yuseff Hamadeh fatally shot 35-year-old Jordan Frazier after police said Frazier pointed a gun at him during a traffic stop on South Acadian Thruway. Most recently, Officer Darrell Carter fatally shot 24-year-old Calvin Toney at an apartment complex on Nov. 13 after authorities said the officer and a Department of Child and Family Services caseworker tried to approach Toney about child abuse allegations.

Moore also is tasked with determining if any criminal charges should be brought against Baton Rouge police Officer Frederick Thornton, who police say fatally struck a pedestrian on Florida Street on June 27 in an unmarked police car. Thornton was on duty at the time.

He said he is also reviewing an Oct. 12 vehicle crash on Airline Highway, which involved an unnamed off-duty Baton Rouge police officer. A 1-year-old girl died from injuries in that crash, authorities said.

Moore said he is unsure when his office will complete those reports. 

Editors note: This story was updated to include the names of the East Baton Rouge Sheriff's detective and SWAT member who were involved in the case. They were released by the East Baton Rouge Parish Sheriff's Office a day after the report. 

Follow Grace Toohey on Twitter, @grace_2e.