DETROIT – Since Dec. 22 when a gunman with an AK-47 opened fire on a car full of teens near Philips and Charlevoix streets, Detroit police have been searching for the gunman and what sparked the shooting. The Liggett stand-out student, 16-year-old Paige Stalker, was killed in the shooting. Three other teens in the car were injured.

Local 4 was the first to report this week that police are moving away from robbery as a motive and now we have more insight into the investigation.

On the record, police aren't committing to anything.

"There's other avenues, the tips are coming in. There's different avenues and we're investigating them all," said Capt. Erik Decker.

Behind the scenes, sources told Local 4 there are two divergent theories on what went down that night and why. Both theories are being explored right now. However, the station will not going into detail because it could impact the investigation.

We can tell you that an arrest that is unrelated to Stalker's murder has turned up information on the case. Police are also taking a closer look at a relative of one of the teens who was in the car that night.

A very generous $100,000 dollar reward is being offered for the tip that leads to the arrest and conviction of the gunman.

Anyone with any information on the shooting is asked to call Crimestoppers at 1-800-Speak-Up.