Coleman, who went by the nickname of Lil Jojo, had recently earned offers from two minor record labels for his songs, according to his family.
Police were also investigating whether gang rivalries played a role in Coleman's death.
Police said Friday morning that no arrests had been made in the shooting.
Across social media, recent tension was evident between Coleman and other rappers, including an associate of a rising star in Chicago's hip-hop scene. On Twitter and in a series of rap videos on YouTube, the two sides are shown "dissing" one another.
Coleman was riding on a bicycle when he was shot about 7:30 p.m. Tuesday near 69th Street and Princeton Avenue, not far from where he grew up and still recorded most of his music. Police said the gunman opened fire from a passing tan or gray car.
Four hours before his death, Coleman posted a tweet that appeared to identify his location. "I'm on #69. I'm out here," it read.
Not long after Coleman was killed, the rising star now with Interscope Records appeared to taunt him in a tweet that read "It's sad cus ... Jojo wanted to be just like us #LMAO" -- slang for "laughing my ass off."
The Tribune is not naming the rappers with whom Coleman was feuding because none of them has been charged with a crime.
Coleman recently released a song online, "3hunna K," which mocked those rappers and their "300 squad," which police say refers to the Black Disciples street gang.
Investigators say Coleman was linked to the Brick Squad, a faction of a rival gang, the Gangster Disciples. The shooting occurred in an area where the Black Disciples and the Gangster Disciples have fought.
With homicides soaring by 32 percent through Aug. 26, city police are also seeing more street gangs turn to social media to incite violence against one another. Indeed, over the last few years, many South Side gang members have created rap videos to taunt and threaten rivals, posting them on YouTube and other websites, veteran gang investigators have said.
Beyond crime-ridden Englewood, for example, Gangster Disciple and Black Disciple members in nearby Woodlawn have committed violent crimes that stem from their rap videos.
"These guys are really gang members who make rap," one investigator said. "This is just a creative way of saying, 'I'm going to get you later.' "
Ald. Willie Cochran, whose 20th Ward includes Woodlawn, said gang members have said they want to be the next big rapper.
The rising rap star, who just turned 17, was recently under house arrest for a gun charge. During that time he was signed to a record deal by Interscope Records, the home of famed rappers Dr. Dre and Eminem, and a few weeks ago he appeared at the Lollapalooza festival.
Other top Chicago hip-hop artists jumped in with Twitter comments Wednesday in reaction to the rising star's apparent mocking of Coleman's slaying. They also weighed in on the rising star's taunts toward Chicago hip-hop star Lupe Fiasco after Fiasco criticized the violence in the rising star's lyrics.
After several hours of mostly negative fallout from his more than 200,000 Twitter followers, the 17-year-old claimed his account had been hacked.
In an interview outside her residence in the Altgeld Gardens public housing complex, Coleman's mother, Robin Russell, wouldn't discuss whether her son belonged to the Gangster Disciples.
"His music was his music," she said. "I didn't get into what he did ... when he left my house. I tried to be there, tried to teach my son the right way. But you can't hold no child's hand every step of the way. So what he did in the streets I don't know about. What he raps about, I don't know about. ... Whatever's going on out there, I don't know."
Tribune reporter John Byrne contributed.