A medium latte from Dunkin’ Donuts could be the smoking gun that helps solve a petty crime in Natick.

A man walked into a retail shop in town on Dec. 16 and asked the clerk if he could try on a pair of loafers.

After the man put on the $100 pair of Rinjard slip-ons, the clerk went to help another customer. That’s when the alleged thief left and never came back, Natick police said. To the officers who responded to the report of the theft, one detail of the case stood out.

A clerk told police that the alleged perpetrator, described as a white male, medium build, with an unshaven face who “likes caffeine,’’ had abandoned his latte as he left the scene of the crime.

So police began their detective work. They went to the nearest Dunkin’ Donuts to ask some questions.

“Now there are a lot of Dunkies out there (and our relationship is strong),’’ Natick police wrote Friday in a Facebook post. “But the closest one sold only one latte in the preceding hour.’’

Officers recovered surveillance video from the Dunkin’ Donuts of the person they believe could be the suspect, Natick Police Lieutenant Brian Grassey said.

Police have now posted the video on Facebook, and are asking for the public’s help in identifying the man.

“The proximity, the time of the event, and the purchase of the latte — coupled with the description by the clerk — it kind of pieced together,’’ Grassey said in a telephone interview.

Grassey, who calls himself the Police Department’s “Facebook and Twitter guy,’’ said the video didn’t get posted until now because he was on vacation.

He said the department follows up on all crimes, no matter how insignificant they may seem. Sharing things on to social media helps police zero in on suspects sooner, he added.

“We often get feedback quickly and we are able to close out a higher number of cases,’’ Grassey said.

“It’s not the crime of the century here. But he probably didn’t anticipate that leaving behind a cup of coffee was going to expose him.’’

Steve Annear can be reached at steve.annear@globe.com. Follow him on Twitter @steveannear.