Right now, Schroer, who's also the department chaplain, is on his way to Houston, Texas for treatment and chemotherapy after recently relapsing with leukemia.
Schroer will leave Evansville knowing full-well that through faith, family and those in the police fraternity are fighting along with him.
In the empty sanctuary at North Woods Church in Evansville, Nathan Schroer finds peace.
In scripture, he finds salvation.
"For God so loved the world, He gave his only Son," said Schroer as he recited John 3:16 from memory. "That whoever believed in Him will not perish but have everlasting life."
"I heard that verse a million times, a million times. And I never realized that it meant that God was after me."
Fifteen years ago, his Lord and Savior finally caught up.
Schroer says he was working at Eastland Mall when members of the Christian rock band P.O.D. came into the store. Schroer says the band offered to give him tickets to their show in Evansville that night. Schroer declined. The band offered again. Schroer again declined.
Schroer then reconsidered and his life hasn't been the same ever since.
A few years after finding his reason, this associate pastor of North Wood Church found his calling.
"Prior to the police department, I played in a punk band," said Detective Schroer. "That was kind of my thing. I needed a job and I hate admitting something like that, but I needed a job. It was suited to the way that God has wired me."
That was eleven years ago.
He worked his way up from motor patrol to the narcotics unit to the sexual crimes unit. He now spends much of his time at Holly's House.
He deals with the sexually assaulted; the broken and oftentimes forgotten. He deals with cases that include child victims and their abusers; cases many consider the worst of the worst.
"We are capable of good things but we are capable of very bad things," said Det. Schroer. "Most of the time, we're all bad but we're not as bad as we could be. I understand that. No matter who I sit across from at the police department interviewing, there is a recognition in me that I'm bad too."
Whether it's Holly's House or the Lord's House, he reaches out to the depraved and preaches to the lost.
But in 2003, this man of faith had his faith tested.
And it started with a prayer.
"If there's anything You can do, get me out of this rut," said Det. Shroer as he recalled his prayer. "Shortly after that, I got leukemia."
"It was a long, hard process that, at one point, almost sent me home on hospice care to not finish the process."
He recovered and returned home to his wife, Lindsey. Doctors said they'd never be able to have kids so the happily married couple adopted a son.
Then Lindsey gave birth to one daughter and then another.
But as a result of his treatment, Schroer would welcome another family member... the bone marrow donor who saved his life.
Who the donor was proved to be a blessing in itself.
"I met a brother I never knew I had," said Det. Schroer. "My mom got to meet the son she had given up for adoption. There were some awesome things that happened through that so I was very grateful to God for answering my prayer."
Schroer hasn't stopped praying ever since.
While in remission, he's continued his work as EPD's Chaplain and associate pastor at North Wood. He tends after many flocks.
But now the flocks have to return the favor.
"My oncologist thought I needed a second opinion," said Det. Schroer. "They confirmed I had relapsed."
After nearly nine years of remission, his leukemia, his old nemesis, had returned.
"I have this desire to walk my daughters down the aisle, to see my kids graduate, I think that's normal," said Det. Schroer as he fought back tears. "But I'm not scared about anything. There's a huge difference. I'm not scared of any of that because God is a better father to them than I am."
Through grace and through faith, through family and through fellowship, Schroer vows to fight leukemia again.
And that, he says, is a blessing worth counting.
"Do I want to live? Sure, I want to live," said Det. Schroer. "But if I don't, God is good."
"God is going to make something awesome out of it and ultimately that's what I'm excited about."
The Evansville Police Department and Holly's House have set up a donation fund to help cover Schroer's inevitable treatment and chemotherapy.
If you would like to help, you can make donations to the fund at Ohio Valley Financial Group on Burkhardt near Vogel. All of the money will go toward travel and treatment expenses.