LAS VEGAS (AP) — Democratic presidential candidates are releasing new gun control plans and embracing proposals to buy back military-style weapons and ammunition after three high-profile mass shootings killed 33 people last week.

Most of the Democrats running in the packed primary have routinely called for requiring background checks on all firearm purchases and banning bump stock devices that mimic automatic gunfire.

In the wake of shootings in Gilroy, California, El Paso, Texas, and Dayton, Ohio, candidates are releasing more detailed plans and embracing federal gun buybacks, where the government compensates people for turning over weapons. Local governments across the U.S. have run such initiatives to get people to voluntarily give up guns.

A look at some of the plans from Democratic candidates to combat mass shootings and toughen gun control laws:

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ASSAULT WEAPONS AND GUN BUYBACKS

Almost all the candidates say they want to reinstate the 1994 ban on assault weapons, which prohibited the sale of new weapons. Some have gone further, proposing ways to reduce the number of military-style weapons owned privately. The most popular is a federal buyback program.

Former Texas Rep. Beto O'Rourke said this week, after the shooting in his hometown, that he would be open to a mandatory buyback of guns, though he didn't specify which kinds of weapons. That's something only California Rep. Eric Swalwell had embraced before he dropped out of the presidential race last month.

Former Vice President Joe Biden and Vermont Sen. Bernie Sanders say they'd push for a voluntary weapon buyback program, in addition to reinstating the prohibition on military-style weapons.

South Bend, Indiana, Mayor Pete Buttigieg stopped short this week of endorsing such a plan. First he wants to ban the sale of new assault weapons, Buttigieg said, "then we can figure out other mechanisms to reduce the number that are circulating out there."

Former Housing Secretary Julian Castro has said he supports a federal ban on assault weapons. He said during a CNN town hall in April that he supports "things like gun buybacks" but did not elaborate on whether he was calling for a federal buyback.

Massachusetts Sen. Elizabeth Warren, Washington Gov. Jay Inslee, Minnesota Sen. Amy Klobuchar, New Jersey Sen. Cory Booker, former Maryland Rep. John Delaney, Montana Gov. Steve Bullock, Hawaii Rep. Tulsi Gabbard, New York Sen. Kirsten Gillibrand and California Sen. Kamala Harris are among those who have said they support banning assault weapons. Harris has also said she would use executive action to ban the import of AR-15-style assault weapons to the U.S.

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WHITE NATIONALISM AND DOMESTIC TERROR

Inslee put forward a plan Tuesday that would direct federal law enforcement agencies to develop a strategy for confronting white nationalism, along with tracking white nationalists and releasing an annual report on domestic terrorism.

His plan also called for barring anyone with a misdemeanor conviction for a hate crime from buying a gun.

Buttigieg's plan, also released Tuesday, proposed a $1 billion effort to combat radicalization and domestic terrorism. The mayor also proposed pushing the Centers for Disease Control and Prevention to study links between white supremacists and gun violence.

While they haven't released specific plans to address white nationalism, Harris, Sanders, Biden and Warren have called for using more national resources to combat it and domestic terrorism.

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LICENSING

Booker, Buttigieg and Inslee have all released plans calling for a nationwide requirement that every gun owner be trained and have a license. Booker also proposed a rule limiting gun buyers to one purchase a month, a proposal aimed at curbing traffickers making bulk purchases in states with weaker gun laws. He also proposed requiring gun owners to report lost and stolen firearms.

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TECHNOLOGY

In his gun control plan, Booker said he will push to require new handguns to stamp identifying information on bullet casings when a shot is fired. Proponents say the technology allows the casings to be linked to the gun that fired them, making it easier to solve gun crimes.

Biden has endorsed the idea of requiring fingerprint-identification technology that only allows a gun to be fired when held by the authorized owner.

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OTHER MEASURES

Most of the Democratic candidates have called for a ban on high-capacity magazines, which allow shooters to fire more bullets without reloading. Almost all of them have also called for a ban on bump stocks, the devices used by the gunman in the 2017 mass shooting in Las Vegas that allow semi-automatic weapons to fire like machine guns. The Trump administration issued a rule banning the attachments in December 2018, but Democratic candidates have called for that to be made more permanent by Congress.

Most of the candidates support "red flag" laws allowing a judge to order guns to be taken from someone deemed to be threat, and there's broad agreement about requiring background checks on all gun purchases. That includes closing loopholes that allow someone to purchase guns before their background check is completed or allow private purchases and transfers without a background check.

Warren is expected to release a detailed gun control proposal Saturday, but she has already said she supports universal background checks and a ban on assault weapons.