Just hours after her only son was gunned down in 2016, Mykia Capers knocked on the doors of potential eyewitnesses.

Every moment of the 1-minute, 37-second surveillance video put out by police was dissected by the grieving mom.

Every social-media platform, mined for leads.

When she discovered what neighborhood the two men she thought responsible for killing her son were from, she plastered the area with fliers, asking anyone with information about his murder to come forward.

It was a message: She was not afraid.

And, she was not waiting on police to deliver justice.

The reality is that with more than half of the city’s homicides going unsolved and city detectives saying that they are overwhelmed by caseloads or stymied by a lack of community cooperation, more families of homicide victims are realizing that the best shot they may have at getting justice is to seek it themselves.

So, the grieving families-turned-citizen-detectives pressure their neighbors to speak up, they pressure the media to keep the cases before the public. They appeal to people who might not talk to police but might talk to grieving parents they feel for, and then they deliver clues, street whispers, even surreptitiously taken photos of suspects to the detectives working their loved ones’ cases.

When I tell Capers that I’m sometimes both awed and angered at how often parents have to turn into investigators in their own children’s murders, she tells me what she’s told other parents:

“When your child falls off a bike, do you wait for that ambulance to come and take them to the hospital if you know that their arm is broken? In cases like this, it’s the same. As soon as it happens, you have to start doing your own investigating. You can’t wait for police.”

It paid off for the Rojas-Garcia family, who credit community pressure for their son’s killer being arrested and sentenced to life for the 2015 death of 34-year-old Alejandro Rojas-Garcia.

It paid off for Lisa Espinosa, who, like Capers, turned her grief into gumshoe until her son’s alleged shooter was eventually arrested in 2016.

And it paid off for Capers, who on Tuesday morning, barring any last-minute delays, will head to the Criminal Justice Center for the preliminary hearing of the two men accused of gunning down her son.

When I checked in with Greg Singleton, the detective on both the Capers and Espinosa cases, he was straight: The mothers’ work was vital in cracking the cases.

In fact, not to take away from the detective’s fine work, but the more I talk to these relentless moms — because yes, they are mostly moms — the more I think they should formalize their efforts.

Find a space. Hang out a shingle, maybe. Recruit others who’ve done the same DIY sleuthing to help other families. Maybe even give themselves a name. Just off the top of my head, I’m thinking the No. 1 Mothers of Homicide Victims Detective Agency, a play off the similarly named No. 1 Ladies’ Detective Agency books and series. It’s not great, I know. They can do better.

When I shared all of this with Capers the other night, and half-jokingly suggested that as a corrections officer, she might be a good person to lead it, she laughed. But something in her laugh tells me that she and the other mothers of homicide victims know there’s some truth here.

There are many much-needed organizations offering emotional support, but nothing gives parents who have lost a child the same solace as knowing that someone has answered for taking their child’s life.

Once a month for the last three years, Yullio Robbins has gone out to the Germantown neighborhood where her son James Walke III was gunned down in 2016 to pepper the area with fliers, an idea she got from another mom. Lately, she’s been joined by other moms, one whose son was killed around the corner, another just four blocks away.

Early on, she’d return to find the fliers had been removed. But she got wise and started to cover them in plastic and staple them.

“They can’t stop me,” she said.

Right, because the best detectives never give up.