The Dakota County Sheriff’s Office is warning residents to be vigilant in retrieving deliveries from mailboxes and doorsteps amid a rash of mail thefts around the Twin Cities this holiday season.

Thieves are looking for gifts, of course, along with cards containing cash or gift cards.

“It happens all over,” said Captain Pat Enderlein of the Dakota County Sheriff’s Office. “It’s a crime of opportunity, so it’s easy.”

Officials said that thieves rifled mailboxes of about 60 houses in Hampton, east of Farmington, last weekend. At least a dozen Farmington residents reported the same thing, sometimes accompanied by vandalism and theft of lawn ornaments.

They’re not the only ones.

While thefts of packages on porches and mail in mailboxes happen every holiday season, this year it seems to be somewhat more prevalent, said Jim Murphy, a detective sergeant with the Farmington police department. He posited that more online shopping might be the cause.

The culprits could be career criminals stealing to support a habit or teens out with mom and dad’s car causing mischief, Murphy said.

In Inver Grove Heights, police nabbed a couple last week who had stolen at least 164 pieces of mail from local residents and in four other east-metro suburbs. The pair, Joshua Edward Ryan and Cynthia Marie Chavez, were caught Dec. 6 after allegedly driving off without paying for gas. When the mail was found in their car, both were charged with felony mail theft, said Lt. Joshua Otis of the Inver Grove Heights police department.

Ryan was also arrested on suspicion of stealing mail in October, Otis said.

All of the mail and packages from Inver Grove Heights — including video games, a sports jersey and other clothes — were returned to their owners.

But three more people reported stolen packages on Tuesday, Otis said.

Much of the theft goes unreported, officials said, because victims aren’t always sure when a crime has occurred.

Enderlein suggested that people use post office boxes or invest in locked mailboxes, available at hardware stores. When possible, people should track their shipments so that they know when to expect them, or ask a neighbor to watch for them.

A final tip: pay attention to people in the neighborhood who don’t belong there, Enderlein said.

Denae Oswald of West St. Paul said she has lost two packages from her doorstep in three weeks.

The first box was worth $900, she said, and was delivered by UPS on Cyber Monday. When she got home, however, it was gone.

“I totally had a meltdown over that,” Oswald said.

That package was insured so it was replaced. But days later, a friend dropped off a sweater and socks, hanging the plastic bag inside her storm door. Thieves also took that, she said.

To prevent future thefts, she’s having packages delivered to work, she said, and will constrain her online shopping.

“It’s frustrating for me,” Oswald said. “I work very hard for my money and what I purchase with it.”