AMNA NAWAZ: A U.S. Senate vote today means, for the first time in 30 years, Congress and the president will block a Washington, D.C., local law, a bill that would overhaul the city's criminal code.

Lisa Desjardins explains the policy and politics at play.

MAN: I move to proceed to H.J.Res.26.

LISA DESJARDINS: The U.S. Senate today legislating for a single city, but on a national issue.

Senators from both parties were poised to reject Washington, D.C.'s criminal code overhaul.

SEN. MIKE LEE (R-UT): Now is not the time to get soft on crime.

SEN. CORY BOOKER (D-NJ): This body now,in a rush of politics, is going to prevent a city from protecting itself.

LISA DESJARDINS: The rare congressional bloc comes amid national headlines and political pressure over crime.

But this issue affects only Washington, D.C., and raises another justice issue: Is it just that Congress overrule the city's wishes?

TROY BURNER, Criminal Justice Advocate: My name is Troy Burner.

I'm a fourth-generation Washingtonian.

LISA DESJARDINS: What's that mean to you?

TROY BURNER: The nation's capital.

There's so much pride and history here.

LISA DESJARDINS: Troy is proud of the city, but not its justice system, which sent him to prison for 24 years in connection with a murder he was nowhere near.

Did you have this with you when you were in prison?

Troy was convicted based on false testimony, and his sentence was long, due to this, a paragraph in D.C. code that is very broad, saying essentially that people associated even indirectly with a crime, like murder, should be charged as if they pulled the trigger.

Now fully exonerated and a criminal justice advocate, he's a, strong backer of D.C.'s reform.

TROY BURNER: It was a thorough, comprehensive, progressive effort to reform the criminal code, consistent with the natural -- the national standard.

LISA DESJARDINS: D.C. spent 16 years on a Herculean rewrite of its outdated code that is over a century old.

The resulting plan more clearly defines crimes, erases most mandatory minimum sentences and lowers some maximum penalties in exchange for a tiered, more tailored system.

City Council passed it overwhelmingly.

Violent crime is down in the District compared to last year.

But homicides have spiked, prompting Mayor Muriel Bowser to veto the measure.

MURIEL BOWSER (D), Mayor of Washington, D.C.: Any time there's a policy that reduces penalties, I think it sends the wrong message.

LISA DESJARDINS: City Council doubled down, overriding her veto.

KENYAN MCDUFFIE, Washington, D.C., City Council: So, all the fearmongering is totally unnecessary, hyperbolic.

LISA DESJARDINS: Then, D.C., hit a bigger hurdle.

REP. JAMES COMER (R-KY): The D.C. Revised Criminal Code Act of 2022 is irresponsible.

It's dangerous.

LISA DESJARDINS: Congress got involved.

The Constitution gives it direct power over D.C. laws, and the Republican-led House pounced.

REP. STEVE SCALISE (R-LA): We see stories of carjackings every day.

And what did the D.C. Council do?

They passed a resolution to get rid of mandatory minimums on many violent crimes.

LISA DESJARDINS: Last month, 31 House Democrats joined Republicans to override the D.C. crime bill, including Congresswoman Angie Craig, who was attacked in her D.C. apartment building the morning of the vote.

After that came the pivotal defeat.

KARINE JEAN-PIERRE, White House Press Secretary: The president does not support the D.C. Council, the changes that they -- that they put forward, over the mayor's objections.

LISA DESJARDINS: President Joe Biden announced he'd sign the congressional override.

He said it was about keeping communities safe.

That move blindsided many Democrats, including those on the D.C. City Council.

PHIL MENDELSON, Chairman, Washington, D.C., City Council: Democrats who have been our friends have not supported us on this legislation because it has become a political issue for them.

LISA DESJARDINS: D.C. Council Chairman Phil Mendelson said this was about fear of ads like these that ran in 2022 attacking Democrats as weak on crime.

NARRATOR: Helping criminals and hurting cops.

LISA DESJARDINS: He says their bill was deeply misconstrued, that it would not lower most sentences.

For example, armed carjacking, a concern in D.C., has long had a maximum penalty of 40 years there.

But the average, actual sentences have been around 15 years.

Thus, advocates say the D.C. plan to lower the max from 40 years to 24 years is still well above most actual sentences.

And Mendelson points out that's tougher than some red states, like Tennessee.

PHIL MENDELSON: Their maximum for carjacking is, I believe, 12 years.

Well, which is it?

Twelve years?

Our average sentence is 15.

Our maximum is going to be 24.

Yet the message that we're soft on crime, while inaccurate, sticks.

LISA DESJARDINS: Back at Troy's house, I ask if he thinks lowering max sentences could lead to more crime.

TROY BURNER: Can we talk?

LISA DESJARDINS: Let's.

TROY BURNER: That's the most asinine stuff that I have heard in my life.

So what we're saying is, that upon committing the crime, somebody is going to take it in their head to say, oh, well, they reduced the time on this.

That's not going to happen.

That's not realistic.

LISA DESJARDINS: Troy still works in D.C., but now lives in Maryland and has some peace.

But he's disheartened that reforms he sees as critical have hit a wall and that others are controlling D.C.'s fate.

TROY BURNER: To have Congress or anyone else outside of who the people of the District of Columbia chose to represent them, have their authority to usurp is a total smack in the face to democracy.

LISA DESJARDINS: Can I ask you what you think about President Biden?

He himself could have prevented this.

Troy is still looking ahead, but no one knows how, if or when D.C. will again try to fix its criminal code.

For the "PBS NewsHour," I'm Lisa Desjardins.