After this outrage Obama did an Executive Order limiting some of the things that Police can get. This was in 2015, then in 2017 Trump lifted than order on purpose for optics.
Now the Democrats in their "Chokehold Bill" (which does far more than Chokeholds and is named The Justice in Policing Act) will prevent the transfer of anything that is considered military grade hardware to go to the states or local police forces and that includes Grenade Launchers.
(This article covers more than the stuff we just talked about.)
https://www.washingtonpost.com/news/powerpost/paloma/daily-202/2020/06/09/daily-202-demilitarizing-the-police-could-be-a-more-fruitful-rallying-cry-for-reformers-than-defunding/5edf0e54602ff12947e87c9e/