'This Week' Transcript: Former Secretary of State Colin Powell

— -- Below is the rush transcript for "This Week" on March 8, 2015. It may contain errors and will be updated.

ANNOUNCER: Starting right now on ABC's This Week: storm swirling. Hillary Clinton under fire over e-mails. Will the storm pass? Are Democrats getting anxious? What she's saying now.

Hitting the trail, we're on the ground with Jeb Bush in Iowa. Can he win over conservatives?

Ferguson fallout: that scathing report from the Justice Department, allegations of discrimination, racist e-mails. Will the police chief keep his job?

And hailing heroes: the 50th anniversary of the civil rights march in Selma. Former secretary of State Colin Powell is here in an ABC News exclusive.

From ABC news, This Week with George Stephanopoulos begins now.

GEORGE STEPHANOPOULOS, HOST: Good morning. We have new developments on all this week's big stories. President Obama has spoken out for the first time on those Hillary Clinton e-mails saying he first heard about them on the news.

In Madison, Wisconsin, there are protests after the shooting of an African-American teenager by a white police officer. The teen was unarmed, but court records show he was party to an armed robbery last year and police say he attacked the officer.

An independent investigation will examine the evidence. All this in a week where the Justice Department revealed a pattern of racist practices in Ferguson, Missouri, against the backdrop of that extraordinary ceremony Saturday.

President Obama leading 40,000 people in Selma, Alabama, 50 years after that bloody confrontation on the Edmund Pettus Bridge.

(BEGIN VIDEO CLIP)

BARACK OBAMA, PRESIDENT OF THE UNITED STATES: We gather here to honor the courage of ordinary Americans willing to endure billy clubs, and the chastening rod, tear gas and the trampling hoof; men and women who despite the gush of blood and splintered bone would stay true to their north star and keep marching towards justice.

What they did here will reverberate through the ages, not because the change they want was preordained, not because their victory was complete, but because they proved that nonviolent change is possible, that love and hope can conquer hate.

(END VIDEO CLIP)

STEPHANOPOULOS: The president took on critics who say that Ferguson proves America has not made progress on race.

(BEGIN VIDEO CLIP)

OBAMA: What happened in Ferguson may not be unique, but it's no longer endemic, it's no longer sanctioned by law or by custom, and before the civil rights movement it most surely was.

Of course, a more common mistake is to suggest that Ferguson is an isolated incident, that racism is banished. We don't need a Ferguson report to know that's not true. We just need to open our eyes and our ears and our hearts to know that this nation's racial history still casts its long shadow upon us.

(END VIDEO CLIP)

STEPHANOPOULOS: Evidence of that long shadow, the Justice Department report on Ferguson. The mayor of Ferguson is standing by for an exclusive interview after this report from ABC's Pierre Thomas.

(BEGIN VIDEOTAPE)

CROWD: Don't shoot.

UNIDENTIFIED MALE: Hands up.

CROWD: Don't shoot.

UNIDENTIFIED MALE: Hands up.

CROWD: Don't shoot.

PIERRE THOMAS, ABC NEWS CORRESPONDENT: In the city that sparked a new national conversation on race, some big questions this morning. Among them, will the entire Ferguson Police Department be dismantled?

ERIC HOLDER, U.S. ATTORNEY GENERAL: If that's what's necessary we're prepared to do that.

THOMAS: The attorney general's blunt response came on the heels of a blistering Justice Department report which found a pattern of racial bias in Ferguson policing.

African-Americans make up 67 percent of Ferguson's population but were 93 percent of all arrests and were the targets of 85 percent of traffic stops.

UNIDENTIFIED MALE: We've been getting harassed so much that we're tired of it.

THOMAS: The report also detailing racist e-mails sent by city employees, one describing the president of the United States as a chimpanzee.

By Friday, three city officials involved were gone, a city court clerk fired and two police officers resigned.

In the fatal shooting of a young black man by a white police officer, this week Eric Holder decided to the to prosecute officer Darren Wilson saying there was not evidence he had violated Michael Brown's civil rights. But he added that the investigation had affirmed some of the concerns of minorities.

HOLDER: Some of those protesters were right.

THOMAS: The president took harsh note, as well.

OBAMA: There was an oppressive and abusive situation.

THOMAS: Mr. Obama said while he believes the overwhelming majority of police are great public servants, he said there are still pockets of discriminatory policing.

OBAMA: And what happened in Ferguson is not a complete aberration. It's not just a one-time thing, it's something that happens.

THOMAS: In the last five years, the Justice Department has opened more than 20 investigations into police departments with prosecutors enforcing 15 agreements, often to correct unconstitutional policing practices. The quest for a more perfect union clearly not over.

For This Week, Pierre Thomas, ABC News, Washington.

(END VIDEOTAPE)

STEPHANOPOULOS: And we are joined now by the mayor of Ferguson, James Knowles. Mr. Mayor, thank you for joining us this morning.

You know, that report so horrifying to so many, shocking in so many ways, and it leads to the question, how could you not know these kinds of practices were going on?

JAMES KNOWLES, MAYOR OF FERGUSON, MISSOURI: Well, I think it's important to recognize that the mayor and the city council in the city of Ferguson are part-time public servants who oversee, you know, we hire a professional staff to oversee and administrate on a daily basis what goes on in the city of Ferguson. And some of these things, these e-mails, absolutely we will not tolerate in this community. They showed some bias that is intolerable and those are things that we acted on immediately, but those are things that as the mayor, as the city council we don't monitor on a daily basis everyone's e-mails. And some of these practices, I think, that have come to light and some of these stories are new to many of us, especially at least the length in which the DOJ states that it occurred.

STEPHANOPOULOS: So now that you know about them, the question is what to do. Attorney General Holder said it might be necessary to dismantle the police department. Are you prepared to do that and to fire the police chief?

KNOWLES: I think what's important right now is that we go through every part of that report, find out where the breakdown was and the patterns and practices and these safeguards that we should have had in place and need to have in place to ensure that we protect the safety and the civil rights of everyone that comes to Ferguson and lives in the city of Ferguson.

You know, very few communities in this country have undergone this level of scrutiny, and the city of Ferguson has after thousands of e-mails have been examined, court documents, arrest records, we know what the issues are and according to the Justice Department with the city of Ferguson.

We're one of the few -- we're the only one in the St. Louis area who has undergone that scrutiny. We know how we can address those issues and we're committed to moving forward to make that happen.

STEPHANOPOULOS: So, what exactly are you going to do? Will the police chief keep his job? Will you implement the kind of recommendations the Department of Justice called for, increasing officer training, more partnership with the Ferguson community, prohibiting ticketing and arrest quotas?

KNOWLES: Well, some of those things -- you know, absolutely we're going to -- I think we can say immediately we're going to be working on improving training, improving some of the outreach to members of our community, to sections of our community, especially who feel underrepresented who have been underrepresented.

One of the things that we're focused on, which will be the only one and the first one in the St. Louis region, is to implement a civilian review board so that civilians can have input into the policies and procedures of the city of Ferguson Police Department but also review and take in complaints against the city of Ferguson Police Department so that elected officials like myself can hear these complaints, can see them come through and monitor this and the civilians will have an active role in that.