The D.C. Council on Tuesday could pass new laws restricting the ability of gun owners to modify weapons and require police to seize guns from people deemed a danger to themselves or others.

The latter provision — known as a “red flag law” — is gaining popularity, with variants implemented in more than a dozen states, including Maryland. Other proposed laws, if passed, would ban the rapid-fire attachments known as bump stocks and increase penalties for extended magazines, accessories that allow guns to fire faster and hold more bullets.

The package, the Firearms Safety Omnibus Amendment Act, unanimously passed the council during its first hearing on Dec. 4. The final vote is Tuesday.

D.C. Council member Charles Allen (D-Ward 6), chairman of the public safety committee, called the package “smart legislation that looks at how we address gun violence.” He said it makes sense to remove, even temporarily, firearms “from someone expressing they will do harm to themselves or others.”

The D.C. Public Defender Service opposed the bills at a public hearing in March, saying it was concerned authorities would have too much latitude to seize weapons. It also said the gun-accessory restrictions are unnecessary because such items are regulated under existing laws.

The measure to allow law enforcement to petition a court to remove firearms and ammunition from a person deemed to be a significant danger to others is called an “extreme-risk protective order.” In November, a police officer in Maryland fatally shot a man while serving such an order after authorities said the man became angry and grabbed a gun.

Bump stocks are used to accelerate the firing of semiautomatic rifles, essentially turning them into fully automatic military-style weapons. They are already prohibited in the District. A bump stock was used by the gunman in the 2017 mass shooting in Las Vegas. The shooter opened fire on a crowd of concertgoers, firing 1,100 rounds, which killed 58 people and wounded 851.

The bill also would add to the penalty for people caught with a gun magazine that can hold more than 10 bullets, increasing it from a misdemeanor with a maximum one-year sentence to a felony that carries a sentence of up to three years. A rifle with a high-capacity magazine was used by one of four shooters who opened fire in a Northeast Washington courtyard in August, killing 10-year-old Makiyah Wilson in a hail of 76 bullets.

The administration of Mayor Muriel E. Bowser (D) supports the package of proposed laws but objects to an immunity clause that says the subject of an extreme-risk protective order who has illegal firearms seized cannot be criminally charged.

D.C. Police Chief Peter Newsham sent a letter to the council noting the objections.

“It will, ultimately, create an environment more accepting of illegal guns and the crimes they are used to commit,” the chief wrote in the letter. He called the immunity measure a “highly unusual and, I believe, counterproductive step” and said extending the protective-order process to protect illegal guns “will undermine efforts to protect the community and other potential victims of violence.”

Allen defended the provision, saying that many times loved ones or friends are reluctant to call police “because they are concerned about the criminal consequences” even though they “want to be able to remove the firearm.” This, he said, “is aimed at making sure people do the right thing.”

Katerina Semyonova, the policy counsel for the D.C. Public Defender Service, testified in March that the bills would add to “confusing and overlapping” gun laws in the District.

Semyonova said gun accessories such as large-capacity magazines “are already amply covered in code.” She added: “There are no gaps in the District’s ability to prosecute illegal possession of firearms. . . . The District does not need new laws for ancillary offenses.”

She also objected to the protective orders, saying her office is concerned that under both provisions, judges and police will be allowed to seize weapons without allowing the owners due process — a chance to object in court.

“As drafted, it makes the otherwise lawful possession of a firearm an unlawful possession as soon as an order is signed by a judge,” Semyonova said. “The bill criminalizes conduct that is protected by the Second Amendment, and the person would have no reason to believe it is against the law.”