DENVER — More than a dozen people from several marijuana dispensaries in Denver were arrested earlier this week.

Police say employees at eight Sweet Leaf dispensaries in the Denver area were selling more than the legal limit of marijuana to undercover officers during a year-long investigation of the retail locations.

Police executed multiple search and arrest warrants during raids at the Denver-area dispensaries Thursday morning. Thirteen people were arrested, and the Sweet Leaf locations targeted in the operation had their licenses pulled and remain closed.

Purchasing more than the legal limit is a term the industry calls “looping.” It’s when a buyer goes into the dispensary, buys the maximum permissible amount of 28 grams, drops the weed off, and then returns to the dispensary to purchase more.

State law allows the possession, use, display, purchase, and transport of one ounce or less of marijuana.

The year-long undercover operation involved officers posing as customers at the eight dispensaries. According to an affidavit, the officers were allowed to purchase more than what is legally permitted on multiple occasions at the targeted Sweet Leaf locations:

During one of the sting operations, an undercover officer was able to enter the same store seven different times in less than an hour and a half and buy pot, the affidavit read.

The 13 employees arrested as part of the operation are facing drug charges of distributing marijuana. Some are facing felony charges because of the amount over the legal limit allegedly sold to the officers. The names of the suspects were released Friday:

Jonathan Sublette

Andrea Cutrer

Stuart Walker

Dana Velasquez

Ian Ferguson

Joseph Gerlick

Natalie Betters

Deann Miller

Leeanne Henley

Krystal Mauro

Christopher Arneson

Cassidy Thomas

Devin Waigand

As a result of the police investigation, the city department that regulates marijuana businesses issued summary suspensions at 26 dispensaries operating under the Sweet Leaf brand.

They include retail and medical marijuana stores, retail and medical marijuana cultivation facilities and one medical marijuana-infused product manufacturing operation, according to city spokesperson Dan Rowland.

Sweet Leaf operates 10 stores in the Denver area. It's not clear how much of its operation has been affected by the raids and the action taken by the Denver Department of Excise and Licenses.

