UPDATED 11/07/11 11:03 a.m.

CHICAGO (CBS) Police continue to search for a motive in a shooting that killed three people near a Chatham neighborhood bakery over the weekend, as they question a person of interest in the case.

As CBS 2’s Susanna Song reports, police are now questioning a 17-year-old boy, but had issued no charges as of 11 a.m.

The motive in the triple murder is unclear Monday morning, but the horror speaks for itself. A 2-year-old girl is now motherless.

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

The shooting happened Saturday evening in the 400 block of East 87th Street, in a parking lot outside A Piece of Cake bakery and a neighboring Church’s Chicken restaurant.

Witnesses picked the Chicago boy out from an array of photos as the person who allegedly shot the three who were all sitting inside a car, police said.

Police said a car pulled up to the parking lot at about 5 p.m. Saturday, just as Chanda Thompson, 21, was leaving A Piece of Cake Bakery and getting into the parked car with two men.

Thompson had been picking up a cake for her daughter’s 2nd birthday at the bakery.

But when she got in the car, witnesses say a man walked up and shot her and her two friends, killing them all.

“I saw this guy just pull up, jump out, and just started shooting,” said witness Valeria Durham, “and I heard, like, boom-boom-boom-boom-boom-boom-boom!”

Jennifer Lias, the assistant manager at Church’s Chicken, 400 E. 87th St., said her cook saw the gunman pull the trigger.

“He saw the man pass him, walk this way, and then he said he saw the man, after the shooting, go right past him and walk to the back, and ran through the alley,” Lias said.

On Sunday, the Chatham community came together at 87th Street and King Drive to get the word out, along with community activist Andrew Holmes.

One of Thompson’s good friends also came out to pass fliers.

“She left behind a baby, a brother, sisters, family – they’re all just shocked,” said the friend, Camiella Williams.

Thompson was pursuing a nursing degree at a local college, and also working at a daycare.

Her daughter’s birthday party still went on Sunday, even though relatives said it was hard to be in the mood.

Authorities have also identified one of the other friends killed as Cortez Champion, 21. The other man’s name has not been released.

The bakery has been operating in the Chatham neighborhood for 30 years.

Retired Mayor Richard M. Daley stopped there for a piece of birthday cake emblazoned with his picture last April while making his farewell tour of the city.

The Sun-Times Media Wire contributed to this report.

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