Benjamin Deen was a self-described "country boy" who loved busting gangs and became the department's police officer of the year after rescuing a family from a burning home.
As authorities build cases against four suspects accused in the killings, friends and family of the slain officers shared memories of two men who they said were proud to be police:
To you, his photo might seem like a snapshot of a 24-year-old policeman slain in the line of duty. But Ronald Tate sees much more.
"This was my baby," he told CNN's Poppy Harlow, "and that's all I see."
Liquori Tate was once a little boy who loved police cars. The flashing lights fascinated him. He scooted around in a motorized miniature cruiser.
For years he followed a path that took him through community college and into a career at auto parts stores. But one day, he told his father that he had a new dream: He wanted to be a policeman.
"He had this enthusiasm, this fire in his soul, and I knew he meant that," Ronald Tate said.
It was something you could see whenever he was suiting up for work, his mother, Youlander Ross, told CNN
"It wasn't just a routine, or 'here we go again, another day,'" she said. "Liquori, every inch of his uniform, he put a lot of honor and dignity into putting on that uniform, from the tie to the cufflinks, he put it on with pride."
That doesn't mean Liquori Tate didn't know he was putting his life in danger when he joined the force.
"He really knew the risk," Ronald Tate said, "but I think my son just thought people ... are generally good people, so let's treat them all with dignity."
Liquori Tate graduated from the police academy last year and trumpeted the news on Facebook
There were photos of him in a crisp new uniform.
Ronald Tate still saw his baby.
The two talked every week and texted every day.
"He was just wonderful," Ronald Tate said. "He was doing what he wanted to do."
The notion "that all police are out to get people or they're bad," Ronald Tate said, simply isn't true.
Liquori Tate was many things, his family said. He was his sister's protector -- they were born just 11 months apart and were like twins. His younger siblings adored him and greeted him like a rock star, shouting out his nickname, "Coco," whenever he came to visit.
He was a man with many friends from many different backgrounds. He grew up in Germany for five years while his father was stationed there in the military.
"My son didn't see color. ... We didn't have all this animosity between races, and my son didn't see that. He didn't have time for that. He was just mellow and laid back and didn't want to get into that," Ronald Tate said.
Liquori Tate, his father said, was so much more than the uniform he was so proud to wear. His family is still reeling and trying to come to grips with his death.
"This was my baby, who I was willing to allow to go into this type of dangerous work," Ronald Tate said. "A guy who understood and loved everybody. Peaceful, passive, understanding. Wouldn't hurt anybody."
At a vigil on Monday, Tate's fellow officers said his joy on the job was infectious.
Assistant Chief Frank Misenhelter said he was struck by Tate's smile from the moment they first met.
"I've never seen anyone more happy to be a cop than him," Officer Jason Jarvis said.
Tate would gleefully turn on his siren, he said, even during their academy training when they'd been instructed to keep quiet. And once he was on the force, officers often heard the familiar sound of Tate's siren on the radio when he was calling in a stop. One day, Jarvis said he asked his fellow officer why he liked the siren so much.
"I just love the way it makes me feel," Tate replied.
Benjamin Deen: 'A damn good friend'
Deen, 34, was dedicated to cleaning up the streets, focusing much of his police work on fighting gangs in Hattiesburg.
"He loved to fight gangs," Misenhelter said. "He loved to identify them and figure out their strategies. He did that feverishly, passionately."
Misenhelter said he quickly bonded with Deen over discussions of gang symbols, signs and tattoos.
"He always had that smile on his face and that old country drawl. ... And when he did something good, and he did a bunch of good things, he'd always find me out and say, 'Chief, ain't too bad for an old country boy.'"
For years, the man known to fellow officers as B.J. and "Deeno," has loved being a K-9 handler, Capt. Peggy Sealy said.
With his dog, Tomi, at his side, they made numerous drug arrests.
Before joining the Hattiesburg Police as a recruit in 2009, Deen had also graduated from the state's fire academy. It was training that came in handy in 2012, when Deen rescued a family from a burning house.
"I reckon that was the fireman in him. He had two sides, fireman and policeman," Sealy said.
Deen was named Hattiesburg's officer of the year after the heroic act, she said.
That year he also became a field training officer and "went out of his way to train young officers," including Tate, Sealy said.
"He always brought training topics that anybody could relate to," she said. "Senior officers, young officers, everybody could relate to him."
In evaluations year after year, Sealy said, Deen's supervisors praised his clear love of his job and his willingness to go the extra mile.
"Deen was proud to wear the badge," she said. "He never dishonored it."
Married with two young children, Deen was a great friend who "had a great love for his family," said Ryan Moore, a reporter for CNN affiliate WDAM and the officer's friend.
"B.J. Deen was a good officer, father and husband," Rob England, a Southern Mississippi Police Department employee, told the Clarion-Ledger newspaper in Jackson, Mississippi. "And a damn good friend."