UPDATE: Police said Thursday that Army reservist Robert Polk, missing since Oct. 3, was found dead in north St. Louis after being shot.

Demolition workers found his remains behind a piece of drywall in a garage.

Family members said he was going to look at a used car advertised on Craigslist before his disappearance.

Read the full report on FoxNews.com.

Original story below.

A St. Louis veteran has been missing since last weekend, when his family believes he left home to meet with someone about a car he saw on Craigslist. 

22-year-old Robert Polk's mother said her son had been working at a temp agency and saving his money to buy a car. 

Hayleen Jones told FOX St. Louis that her son was excited because he believed he had finally found a car on the popular website.

“[He] went to go meet the person to buy the car. He’d been talking to someone about a black Mustang and has not been back since,” she said, fearing that her son "met up with the wrong person."

Polk, a standout football player in high school, served two years in the Army and is still on the reserve list. 

She believes her son would not have left for more than a day without calling. 

Anyone with information is asked to call the St. Louis Metropolitan Police Department at (314) 444-5309.

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Police around the country have stressed safety tips in recent years after seeing a rash of robberies and other crimes linked to Craigslist sales. 

Among the tips they offer: 

- Don't go to the meeting alone. 

- Meet at a public place. Some police departments suggest using the parking lot of the local police precinct. 

- Do not invite a stranger into your home or go into a stranger's home.

- Bring your cell phone and let a friend or family member know where you're going.

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