How do you solve a gun problem like Chicago?

It's a place where more young Americans have been murdered in gang violence in the last twenty years than in both the wars of Iraq and Afghanistan combined.

So how do you solve a problem like Chicago? Not with incendiary tweets – that’s for sure.

But President Trump’s threat to “Send in the Feds” (which some have taken to mean the army) has put America’s Windy City back on the political agenda.

And it took me back there to assess Chicago by night and meet those caught up in its endless cycle of violence.

We were following TJ, a young journalist dubbed the night crawler, who listens to police radio so he can get to gang shootings first and sell his footage fast.

And in 48 hours we listened to the endless crackle of panicked voices and gunfire over his radio before arriving at the scene of Chicago’s latest bloodletting.

There were so many gun battles the night time has blurred into a memory of ticker tape and blood. But I won’t forget the scream of the sister who arrived home to find her young brother had been fatally shot.

TJ has seen it all. He says the gang members kill with impunity – sometimes in front of the police – and bringing in more guns would only add to the mayhem

He says what Chicago needs is to bring more of the criminals to justice so those who murder are scared of the consequences. More than 70% of Chicago’s killings are unsolved.

The murder of De'Arrea Haymond, 19, last year is among those which have never been solved.

“Forgive me.” Her daughter tells me as tears roll down her face. “I have to be strong for my granddaughter”, four-year-old Maliah.

She remains desperate for justice. No one has ever been arrested or charged for this drive-by shooting, adding to the sense of hopelessness.She supports Trump’s call for more guns and more troops. “Anything…” she weeps.

Dean Angelo, the head of the city's Police Federation, recently met the President. He feels that the rhetoric coming out of the White House has been helpful and supportive to the police who are often “afraid to do their job” in an atmosphere of mistrust.

The shooting of teenager Laquan McDonald in 2014 severely strained relations with the police. Police dashboard camera shows the young black man was shot 16 times, including when he was lying on the ground, by a police officer now on trial for murder.

Dean Angelo says more important than any use of Federal troops would be to increase sentencing of those arrested for gun crimes. Tougher federal sentencing and stronger policing are what he believes would help this city.

Chicago, a Democrat city and the birthplace of former President Barack Obama, is a place of two halves.

The prosperity of the river front on the North side of the city is a world away from the derelict properties on the South and West Side.

Those who live here say the solution to Chicago’s problems lies with more long-term investment. The Democrats here say Trump is politically motivated and simply attacking Obama’s legacy.

Head teacher Michael Holmes has spent his life raising boys in the eye of the gangland storm. He is proud of his school and his pupils – nearly all of whom manage to stay out of trouble.

He says many of the pupils arrive at his school suffering from PTSD because of the violence they encounter in their daily lives.

I spoke to a classroom of boys who were inured to what they see around them. Cycling home avoiding gun battles? Part of a normal school day for some.

Holmes says the city’s children who do join the gangs often have no other choices. There are many here, he says, caught up in a cycle of violence; many with drug addicted mothers, absent fathers and no hope of a job.

He says that building a city they can believe in and which offers them a future is the only way out of the violence. “Sending in the Feds? That’ll make it worse”, he tells me.

I spoke to those, whose lives have been destroyed by the violence, who want better justice, and I spoke to the police who want greater punishment.

But those trying to help the young people want more understanding and investment in the city.

All of these would help Chicago. The President’s tweets and the threats have so far done no more than rekindle a debate about the tragedy and waste that is a daily part of the lives of many in America’s third city.