By Charlie De Mar

CHICAGO (CBS) — A teenager accused of killing a beloved grandmother in Chicago’s Hegewisch neighborhood will soon appear in court. It took just 11 days for Chicago police to make an arrest in the case, and now a 17-year-old will be charged as an adult in the death of Yvonne Ruzich.

Most of Ruzich’s family and friends were together celebrating her life as they got word of the arrest.

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Police arrested the 17-year-old for walking up to her car and immediately shooting the 70-year-old as she waited to go into work at a Hegewisch convenience store. Police say she tried driving away but crashed. The shooters returned and fired several more rounds into the car.

Her stepson was able to escape.

“I lost my best friend in the world over a car,” said Ruzich’s boyfriend Phillip McGivney.

He and a church full of friends and family learned of the arrest Friday during a mass for her.

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“Everyone clapped and stood up,” he said. “It was just unbelievable, justice being served.”

Police say the people in the video of the shooting were after her car, but they never took it.

Detectives tracked the stolen car the shooters were in to a spree of previous carjackings in Illinois and Indiana, which led them to teh 17-year-old who is now charged with first degree murder.

“It’s been a horrible couple of weeks. Such a wonderful woman,” said McGivney.

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Police say they are still looking for the second person involved in the shooting, who is also believed to be a minor.

Charlie De Mar