Simon revealed that while Avon’s character is mostly based upon Williams, his name and some of his characteristics are taken from Nathan Barksdale, whose middle name was Avon. Nathan and Avon were both boxers, and one of his rivals coming up was Timmirror Stanfield – the inspiration for Marlo.

Avon’s actor Wood Harris even works with Nathan Barksdale in the Legends of the UnWired documentary

https://www.youtube.com/watch?v=6V2U8XmQSR8

Simon employed the inverse technique when coming up with the name for Bodie Broadus and Avon Barksdale; he took Nathan Barksdale, whose middle name was Avon and nickname was “Bodie”, and turned him into the name for two different characters.

Fun fact – Williams was arrested by Wire writer Ed Burns, and the arrest was covered in The Baltimore Sun by David Simon. The interesting part? His downfall came large in part thanks to a wiretap very similar to the one used to take down Avon in Season 1.

The Deacon is a well-known and respected member of West Baltimore, maintaining connections with everyone from soldiers like Cutty, to high-ranking officers like Colvin, to important politicians like Delegate Watkins.

Eh, I can see the resemblance

Requer is a Baltimore Police Department night patrolman and former partner of Lester Freamon. He only gets one notable scene, where he is talking to McNulty and Freamon about real estate, revealing that it’s a “buyer’s market out there” – which turns out to be the epigraph for that episode.

“The Bunk is strictly a suit and tie motherfucker”

https://www.youtube.com/watch?v=7o1jTGK0Lqk

Donnie Andrews takes credit for one of Omar’s most famous traits, his code that allowed him to retain some morality despite his line of work:

Q: [Omar]’s a character who lives and dies by his code. Is he sympathetic to you?

Yeah. He had his moments, like when I was out there. You know I might do something or beat somebody, then go home and think about it. Or I might take somebody’s money, but then I’d always leave them with something. You had your moments, and they made Omar exactly the way I was.

Donnie Andrews reveals that the choice to make Omar gay was inspired by Outlaw, who was “a gay stickup guy”.

In an interview, Andrews revealed that Omar was not the first character in a cop drama to be based off of his life; someone else beat David Simon to the chase

“The first Omar was in NYPD Blue. Giancarlo Esposito played him, in an episode called Hollie and the Goldfish. He did a thing where I had robbed some Cubans.”

Andrews' wife, Fran Boyd, revealed that she didn’t realize Omar was based on Donnie until watching the show for herself:

“The first time I knew it was Donnie,” says Fran, “I was watching an episode; there were three drug dealers in a house. They had trash bags full of money and drugs, and Omar walks up to the house with a shotgun, knocking on the door. And the guy peeps out, whispering, ‘Hey man, Omar’s here.’ And they’re sitting in there, wondering what they’re gonna do. And Omar turns his back and says ‘I’m giving you all 10 seconds’. These people in the house have guns, all they have to do is come through the window and blow his brains out; the next thing you know, these bags come flying out the window. It clicked, because I remembered Donnie telling me that story. I said: ‘David, the motherfucker!’ And I jumped on the phone and I said, ‘David, is Omar really Donnie?’ He said ‘No, that’s not Donnie, what you talking about?’ I said; ‘You’re a damn liar.’ He finally broke down and told me it was Donnie.”