He’s a serious Catholic and a serious cop.

Only Boston Police Commissioner Bill Evans knows which comes first.

On Monday, Evans spent a rainy day with his officers patrolling the legendary Boston Marathon route where, two years ago, the Tsarnaev brothers set off their deadly bombs.

The next day, jurors began hearing testimony in a Boston courthouse on whether the surviving brother, Dzhokhar, will live or die.

And Evans repeated to me what he first told me days ago about the death penalty for the man who killed four and wounded more than 260 in the worst terrorist attack in the United States since 9/11.

“I’m torn,” Bill Evans said in his sprawling headquarters office decorated with pictures of several presidents – and the pope. “I’m still torn.”

Yet Evans saw the blood and carnage at the marathon finish line.

With three other officers, Evans was the first on the scene in Watertown, the Boston suburb where Tsarnaev was found hiding in a shrink-wrapped boat. Evans shouted for a cease-fire when police started shooting up that boat.

And Evans repeatedly watched the now infamous video showing Tsarnaev right behind Bill and Denise Richard’s three children — for a full four minutes — before he left his bomb beside them, killing Martin Richard, 8, and taking the leg of Jane Richard, then 6.

“I’m a big Catholic. I’m going to church all the time,” Evans said. “My leader (Boston Cardinal Sean O’Malley) has come out against [the death penalty]. And I don’t believe [Tsarnaev] should be killed.

“But the law enforcement part of me …” Bill Evans said, then paused. And then said he hopes jurors do what they think is right.

That’s an unsurprising perspective for a Catholic, a totally surprising one for a cop.

There’s more about Evans that surprises.

Last month, when an African-American suspect shot a white Boston police officer in the face — and then was killed by police — tempers flared in the minority community. This is the year, after all, when black men keep turning up on the news, shot dead by white police officers.

Yet when Bill Evans spoke to reporters, he spoke not only of his critically injured officer, but also offered condolences to the family of the dead man, a felon with a long, violent record.

Asked why, he said, “My heart still goes out to them because that’s their child. That’s their husband …. There’s people hurting no matter the circumstances …. There are no winners here.”

And last fall, when protestors in Boston demonstrated over the Michael Brown shooting in Ferguson, Mo., Evans pledged a gentle, peaceful police approach — no show of force, no cops in the helmets and riot gear we saw in Ferguson — but in the same blue uniforms they wear every day. News coverage of those and other protests showed police reacting to considerable provocation with considerable restraint.

This certainly doesn’t mean Boston’s police ranks are free of bad actors, but the message from the top is very clear and very unusual. It’s not about confrontation, power, and force, but keeping the peace.

You ask around Boston, you hear that Bill Evans is a tough cop, a cop’s cop, but also a calm and thoughtful cop who wants to build strong relationships between police and the neighborhoods they patrol.

You hear about his motto, “Kill ‘em with kindness.” It’s left over from when he managed to extricate Occupy Wall Street protesters from their makeshift downtown camp without the heavy-handed police tactics and mass arrests seen in cities across the country. Famously, he even gave Occupiers his cell phone number.

Here’s what else you hear.

“That he’s a man of faith,” says the Rev. Jeffrey Brown, a long-time non-violence crusader and leader of Boston’s Twelfth Baptist Church.

In a city not known for such public admissions, Evans readily credits his faith and his Church for shaping his life and his policing.

The youngest of six brothers, he grew up sharing a crowded bedroom on the second floor of a triple-decker in South Boston, once a predominantly Irish Catholic neighborhood. He was the son of a homemaker and a forklift operator at the old newspaper, the Boston Herald American. The Gate of Heaven Parish and school were at the center of family life. So was the legendary parish priest there, the late Rev. Paul White.

The Evans boys endured much tragedy.

Evans’ mother died of ovarian cancer when Evans was just 3 years old. A brother two years older than Evans was killed by a hit-and-run driver, never found. When Evans was 14, his father died of a heart attack.

Through all this, Evans said, Father White was there, “sitting with us at our house at the kitchen table. He married all of us. He baptized all of us.”

And when a now-fatherless teenaged Evans started spending too much time hanging on the corner, Father White took notice. “He rescued me, basically,” said Evans, helping him win a full scholarship to St. Sebastian’s, a Catholic boys high school where everyone wore jackets and ties except Evans, the orphaned city kid, who took three different buses to get there and sometimes showed up in overalls with a mismatched shirt.

All that taught him “that there’s really no such thing as a bad kid out there. When I see these bad things happen to kids who don’t have a fair chance in life, I say, ‘there but for the grace of God.’ I think the best thing you can do is give somebody a break. Put yourself in their position. Think how you would want to be treated. Look out for each other.”

It sounds a bit like Sunday morning catechism, doesn’t it?

Bill Evans is an unlikely big city police chief. Surely he doesn’t look the part. An avid marathon runner himself (he’s closing in on 50 races run), he stands 5-feet, 9-inches tall, weighs 133 pounds, and looks as gaunt as a man on the 99th day of a 100-day juice fast.

But this Catholic cop says he loves what he’s doing because he has a chance to really make a difference. “I want to make sure we’re the best police department we can be, and that we’re out there every day,” he said, “trying to help people.”