House Democrats led by Reps. Mike Thompson, Val Demings, Joe Neguse and Ed Perlmutter sent a letter to Joe Biden asking for “Executive Action to regulate concealable assault-style rifles, like the firearm used in the recent tragedy in Boulder, Colorado.”

According to a news release from Thompson’s office, the letter was signed by 101 of their colleagues.

CBS News is reporting the alleged killer in the Boulder mass shooting, which occurred in Neguse’s district, used a semi-auto Ruger AR-556 pistol purchased a week before the attack that left 10 people, including a Boulder police officer, dead.

The suspect, Ahmed Al Aliwi Alissa still has not provided a motive for the attack on a Boulder supermarket. His attack came a week after a Georgia man opened fire at three different spas in the Atlanta area, killing 8 people.

Here is a text of the letter, which is available at Thompson’s congressional website:

Dear President Biden,

“The House Gun Violence Prevention Task Force calls on you to take strong executive action to address serious inequities in the implementation of the National Firearms Act which is the federal law regulating the manufacture, transfer, and possession of certain classes of firearms. For too long, gun manufacturers in order to circumvent the National Firearms Act have designed and marketed concealable AR-15 style firearms which fire rifle rounds.

“Concealable assault-style firearms that fire rifle rounds pose an unreasonable threat to our communities and should be fully regulated under the National Firearms Act consistent with the intent and history of the law. The recent tragedy in Boulder, Colorado where 10 people including a police officer were killed is one in a string of deadly incidents involving this style of weapon. On February 6, 2019, Milwaukee Officer Matthew Rittner was killed by an AK-47 style concealable weapon while trying to execute a search warrant. Later that year on August 4, 2019, a concealable .223 caliber AR-15 style firearm was used to kill 9 people and injure 17 others in Dayton, Ohio in less than 1 minute.

“The National Firearms Act has proven to be extremely effective in preventing crimes with the classes of particularly dangerous firearms it regulates through a system requiring a background check, submission of photo identification and fingerprints, and registration of the firearm with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). The 1934 law sought to regulate certain weapons because of their frequent use in crime. Some of the features exploited by criminals and included for enhanced regulation under the NFA include, sawed off shotguns, rifles with short barrels and weapons with a high capacity of firing like machine guns.

“The concealability and ability to use ammunition capable of penetrating body armor make these firearms especially dangerous on our streets and for law enforcement personnel. We thank you for your commitment to preventing gun violence and urge you to immediately promulgate regulations to cover these concealable assault firearms under the National Firearms Act.”

CBS News is reporting the White House is “mulling executive actions on gun control.” White House Press Secretary Jen Psaki told reporters last week, “Executive actions are of course an important lever that every president has at their disposal. There is current discussions and analysis internally of what steps can be taken. That has been ongoing for several weeks, even before these two recent tragedies.”

She indicated that some Republicans appear open to a “debate and a discussion.”

But grassroots gun rights activists writing on social media are apprehensive. The common complaint is that “compromise” typically means giving up some piece of their gun rights with nothing tangible in return