The Lakewood Church shooter had encounters with more than 50 officers. Nobody stopped her.
There's a lot more in the article where this came from:
In 2016, HPD officers forcibly committed Moreno to psychiatric treatment after the longtime Houston resident told staff at a mental health center that she suffered from bipolar disorder and “began hearing voices telling her to blow the place up,” records show.
Under federal law, any person who has been “formally committed” to mental health treatment by a “lawful authority” such as a court is banned from owning firearms. It remains unclear whether a judge issued a court order formalizing Moreno's involuntary commitment and triggering the gun ban. The Bureau of Alcohol, Tobacco, Firearms and Explosives, which enforces firearm laws, declined to comment, citing a pending investigation.
Yet, for years, Moreno faced no consequences when she flashed pistols in front of police officers and sheriff’s deputies, or when she threatened to use her growing arsenal of war-style rifles to harm people close to her on recorded 911 calls.