The alleged pilot, who was standing across the street, was questioned by agents.
Clinton brought her campaign to Chicago to rally support among minority voters and raise money.
Sandra Bland's mother, Geneva Reed-Veal, joined Clinton at a rally in the city's Bronzeville neighborhood on Wednesday. Bland's death in a Texas jail cell by hanging after a controversial traffic stop by a white officer has raised questions about racial inequality in the criminal justice system.
This is the second time Clinton has visited the Parkway Ballroom in Chicago's Bronzeville neighborhood since she announced she was running for president. During her last visit, Clinton met with childcare workers to talk about rising childcare costs.
"I think police brutality definitely needs to be addressed. I don't think that's gonna change overnight. I think this is a step toward change. I have hope Hillary will be a part of that," said supporter Aleta Clark.
"She has to. We are targets right now. We are an excuse for them to do whatever they want to do," said supporter Erik Hulon.
After the rally, Clinton is attending three private fundraisers in the area with tickets going for $2,700 and up.
Bland's mother praised Clinton as she was introduced.
"Here's a woman who has shown time and time again, that she has the skill, experience and staying power more than 20 years in. Yes, there was Benghazi and the infamous email situation, but while both were stressful she maintained her poise and dedication," Reed-Veal said.
The secretary of state was also joined by other mothers of gun vioelcen victims - Cleopatra Cowley-Pendleton, mother of Hadiya Pendleton; Pam Bosley, mother of Terrell Bosley; and Annette Nance Holt, mother of Blair Holt.
"Looking at pictures of their children, hearing the stories, and the resolve in their voices that they want to do everything they can to help prevent any other mother from going through what they have gone through," Clinton said. "People talk about how powerful lobbies are in Washington and they are big money, big oil. drug companies, insurance companies but I don't think there is a more powerful lobby than the gun lobby. Because what it is able to do is intimidate people, intimidate elected officials."
Clinton is neck-and-neck with Democratic candidate Vermont Senator Bernie Sanders. His crew is opening their Illinois headquarters on Wednesday.
"With Hillary Clinton facing three different investigations from the State Department and the FBI, and her inability to fend off Bernie Sanders, Clinton's campaign is far behind where she intended to be in Illinois," said a statement by the Republican National Committee.