UPDATED 04/01/11 8:37 a.m.

CHICAGO (CBS) — A key clue may help investigators find a suspected robber who pushed a 68-year-old grandmother to her death down a flight of stairs at the Fullerton ‘L’ stop this week.

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Police released a sketch of the suspect on Thursday, and a retired Chicago Police officer in the far northern suburbs says he thinks he saw the robber – more than 30 miles away from the crime scene that day after the incident.

The wake for the woman killed in the Monday afternoon incident, Sally Katona-King, is scheduled for today from 3 p.m. to 9 p.m. at the Grein Funeral Home, 2141 W. Irving Park Rd. The funeral will be held at Grein on Saturday at 10:30 a.m., and is open to the public.

Katona-King was pronounced dead Tuesday, the day after the robber pushed her as he ran away with an iPhone he had stolen on a CTA Brown Line train. She was sent tumbling down a flight of stairs.

On Thursday, detectives working the case told CBS 2’s Mike Parker they have “a lot of tips” from the public.

One of them is from retired Chicago Police Officer Greg Jacobs, now of Mundelein, who thinks he saw the suspect responsible for the death of Katona-King in a cell phone store a the Westfield Hawthorn Shopping Mall in Vernon Hills.

On Thursday afternoon, police passed out sketches of the suspect, who is described as an African-American male, 17 to 25 years old, 5’11” to 6’4″ tall, weighing 170 to 220 pounds. He was wearing a black hat, black jacket with the letters “WS” on the back and blue jeans.

Chicago police have released this sketch of a man suspected of knocking down Sally Katona-King, 68, on Monday after stealing a person's iPhone at a CTA station. Katona-King died a day later. (Credit: Chicago Police Department)

Upon seeing the sketch in the Hawthorn Mall parking lot Thursday, Jacobs said, “That’s him.”

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Jacobs said he saw the suspect with two other men in the Best Buy Mobile store at Hawthorn just before noon on Tuesday.

“The way they walked into the store, they weren’t legitimate customers,” Jacobs said.

Jacobs said recognized the man right down to the jacket with “WS” on the back. He says the man and the other two with him appeared to break into a locked compartment for high-priced phones, then fled when Jacobs approached them.

“I’m 95 percent certain that’s him,” Jacobs said.

The cell phone store has a working surveillance camera, and Chicago Police are indicating serious interest in viewing it.

Meanwhile, Ald. Vi Daley (43rd) is taking issue with the fact that the only security camera at the recently-rehabbed Fullerton ‘L’ stop is downstairs in the entry area.

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“We have a camera facing the turnstile but we have nothing upstairs,” Ald. Daley told WBBM Newsradio 780’s Steve Miller. “We really should have (cameras) on platforms.”

Belmont Area Police Detective Cmdr. Gary Yamashiroya says that obviously more cameras are better, but he says if they’re not pointed in the right direction, they’re no help.

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He says police are reviewing security video from the area, taken around the broad daylight time of the deadly attack.