Police in Waukesha, Wisconsin, seized four packages containing a total of 32 pounds of marijuana from a family who had California weed shipped to their home last year, an investigation by Fox6Now revealed Tuesday. One of the packages contained nearly $50,000 worth of marijuana.

Law enforcement became aware of the delivery scheme in December. “They do try to hide the parcels -- the proceeds and contents of the parcels -- but our detection program is very good,” Postal Inspector Brian Haraway told Fox6Now.

The ringleader of the operation, a man named Shawn Collins, had the pot sent to his sister Shannon Collins’ home. She lived with her boyfriend, Angelo Tagliavia. All three were arrested and face multiple charges, including possession with the intent to distribute. Shawn Collins reportedly died last week, according to Fox6Now, however the circumstances of his death were unclear.

More marijuana has passed through U.S. mail in recent years than any time before as drug traffickers have increasingly shifted from driving marijuana across state lines to shipping it. Confiscations of marijuana packages have increased by more than 400 percent over the past eight years, according to ABC News. Everyday items such as canned goods or plastic paint buckets have been used to conceal the drug for shipment, with smugglers often matching the weights listed on the labels.

The sometimes ambiguous legal landscape has meant that shipping services, which have had to balance a customer’s right to privacy against state and federal laws, have faced scrutiny for drugs being sent through their systems. In January, FedEx was found not liable for delivering a package full of marijuana to the wrong address, a federal appeals court decided.  

Although states continue to soften their marijuana laws or legalize its use for medical or even recreational purposes, shipping it across state lines has remained a federal crime. Private mail carriers such as FedEx have prohibited shipping "[a]ny item otherwise prohibited by federal, state or local law, rule or regulation” through their systems.