GEOFF BENNETT: Last night, the state of Missouri# executed 55-year-old Marcellus Williams over the## objections of the local prosecutor and against# the wishes of the murdered victim's spouse.

Williams was convicted of the# 1998 murder of Felicia Gayle,## who was stabbed more than 40 times# in her home in suburban St. Louis.

As William Brangham explains, Williams maintained# his innocence throughout decades of incarceration.

WILLIAM BRANGHAM: Geoff, no physical evidence# ever linked Marcellus Williams to that crime## scene, and there was only one Black# person the jury that convicted him.

Earlier this year, the St. Louis county# prosecutor filed a motion to overturn the## conviction, calling it a -- quote -- "manifest# injustice."

It cited a lack of credible evidence,## ineffective trial counsel, and racial# discrimination in jury selection.

For more on this case,## we are joined by Jonathan Potts.

He was# Marcel.. Jonathan, thank you so much for being here.

I# know this has got to be an awful day for you all.

And I wonder if you could just# -- how are you doing?

How's the## defense team doing?

How's# Mr. Williams' family doing?

JONATHAN POTTS, Attorney For Marcellus# Williams: Thank you, William.

As you can imagine, everyone's devastated# right now.

It's be.. draining past 72 hours.

There's been# a lot of effort and a lot of support## to keep Mr. Williams alive, but,# obviously, we failed last night.

And when that failure happens, you take# it personally, and you take it hard.

WILLIAM BRANGHAM: Do you believe# in your heart of hearts that the## state executed an innocent man yesterday?

JONATHAN POTTS: Yes, of course I do.# We don't take these cases unless we## believe in our clients, and that's# why we fought for him for years.

WILLIAM BRANGHAM: I know that just on Monday you## were even arguing his appeal in# front of the state Supreme Court.

And one of the things you# were arguing about was the## DNA that was found on the murder weapon# in this case.

Can you tell us what## was going on there?

JONATHAN POTTS: Yes.

So, years ago, we found DNA on the murder# weapon, which was a bloody kitchen knife,## and that actually led one of the prior governors# in Missouri to halt Mr. Williams' execution back## in 2017.

It's always been believed by us that# DNA was going to belong to the true killer.

And as we were systematically excluding# everyone, what we found out is that the DNA## on the murder weapon belonged to the original# trial prosecutor.

At a hearing last month,## the trial prosecutor admitted that he'd# been handling the bloody kitchen knife## without gloves five times before# trial, contaminating the evidence.

WILLIAM BRANGHAM: How do you# make sense of all of this?

I mean, despite the objections of the# current occupant of the prosecutor's office,## who didn't want this to go forward, Ms.# Gayle's own family, this tainted DNA## evidence that you're describing, how do you# explain that this execution still took place?

JONATHAN POTTS: I think you have# to look to leadership that's not## being responsive to the communities# that they're supposed to be serving.

Now, to be clear, as you said, the# local prosecutor's office recognized## that this was not a fair trial.# And they were the ones who filed## the motion asking a court to throw out# Mr. Williams' conviction death sentence.

We were locked arm in arm.

And what the family# has said is they never wanted a death sentence## in the first place.

And yet here they were# 20 years over and still having to deal with## this.

The victim didn't believe in the death# penalty.

The victim's husband didn't want Mr.## Williams to be executed;.

And then the rest# of her family didn't want him to be executed.

It was state-level leaders who were pushing# this through, despite the public's concerns.

WILLIAM BRANGHAM: The current governor of# Missouri, Mike Parson, supported the state's## action, was encouraging that this execution# go forward.

He put out a statement yesterday.

I want to read you a part of it.

He wrote:# "Mr. Williams has exhausted due process and## every judicial avenue, including over# 15 hearings, attempting to argue his## innocence and overturn his conviction.

No# jury nor court, including at the trial,## appellate and Supreme Court levels, have ever# found merit in Mr. Williams' innocence claims."

What do you say to the governor's response there?

JONATHAN POTTS: I say that he didn't# receive due process.

And that's## exactly why the trial -- that the prosecuting# attorney's office was trying to correct this.

There was an execution that was set just a# few months ago and everyone was scrambling## trying to stop this.

And in a hearing that# just occurred just a few weeks ago, we heard## for the very first time from the original trial# prosecutor from 20 years ago where he admitted## that he had removed at least one Black juror from# the jury because, in part, that person was Black.

Now, you can talk about 20 years of due process,# but we didn't hear about that until a month ago.

WILLIAM BRANGHAM: I mean, every year --# I mean, apart from this particular case,## every year, on average, there's# -- I think it's four cases where## someone who is on death row is found to# innocent, is exonerated, and is set free.

I'm just curious what you think this# case reveals about this broader system## in our country to execute people, when# the evidence really can be questioned.

JONATHAN POTTS: I think that the important# message that I hope people will take away## from this is that the public knows# that the justice system isn't perfect.

All those exonerations that you're# talking about, the public sees that,## and the public accepts it.

What the public wants# to hear is that, when the system makes a mistake,## it is going to admit that mistake, it's going to# fix it, and it's going to promise to be better.

That's not what happened here.

This is# a typical scenario where there's a fear## about admitting that you are wrong because you# think that it's going to undermine public trust,## but it's really that resistance# that's undermining the public trust.

WILLIAM BRANGHAM: All right, that is Jonathan# Potts, the lawyer for Marcellus Williams.

Thank you so much for talking with us.

JONATHAN POTTS: Thank you, William.