Police said there were several sightings of Jahmeshia in the two weeks she was missing from home. They also say that they believe she was killed in the 24 hours before she was found and that her body was dumped in an alley after the fact.
Friends and family remembered Jahmeshia Tuesday night at a vigil. Her body was found near 64th and Marshfield, about a block from her home.
Those at the memorial surrounded Jahmeshia's mother, trying to comfort her. She and other family members say they tried to get the word out that Jahmeshia was missing, but they believe police and the media did not take them seriously enough.
Chicago police say they did take the case seriously, canvassing the neighborhood and passing out fliers. Police also say they forwarded a missing person's alert about Jahmeshia to the media.
Police added that they are now using surveillance footage from the area to try and retrace Jahmeshia's last steps.
A memorial was set up near the spot where a passerby found Jahmeshia's body.
"Whoever did this to her, please come out, please do, please," said Sheila Powell, cousin.
Jahmeshia's mother was surrounded Tuesday night by family and friends trying to comfort her. Among them was the mother of another young murder victim.
"It just hurts me to see that this child being reported missing, to me, wasn't taken serious enough for people to get out here and do what they had to do to prevent us from being here today," said Sabrina Harris, victim Ryan Harris' mother.
"When someone is missing, we should be more diligent about putting their faces on the TV, whether there's an Amber Alert or not," said Powell.
Congressman Bobby Rush says authorities assumed Jahmeshia had run away from home, despite word from family that she had spent the day at church before boarding a bus for home.
"The entire community should have been alerted," said Rush.
In a news conference Tuesday, police denied they failed to take the case seriously, saying they have no missing person classification for runaways.
"From the beginning, this case was given the priority attention it deserved because she was only 12 years old," said Dep. Supt. Steve Peterson, Chicago police.
ABC7 News contacted police on several occasions to ask about Jahmeshia's disappearance after the family contacted us. However, we never received an alert from police.
Congressman Rush has pledged to raise a $10,000 reward to help find the killer.
The family has set up an account for Jahmeshia Conner. It is the Jahmeshia Conner Foundation at TCF Bank. Anyone interested in donating can make a deposit transaction at any TCF Branch across the city.