The killer at the heart of Trump's racist ad was set free—by Arizona sheriff Joe Arpaio - Daily Kos

Donald Trump announced at the outset that he wanted this election to be about racism and, despite a few pesky bombs and a mass murder, that has certainly been the core focus of his rallies and statements going into the midterms. ....
https://www.dailykos.com/stories/1809302

Trump’s new immigration ad was panned as racist. It was also based on a falsehood - The Washington Post

It blames Democrats for an undocumented immigrant murdering two cops, but the man was released by Sheriff Joe Arpaio's office and returned to the country twice under President George W. Bush. ....
https://www.washingtonpost.com/politics/2018/11/02/trumps-new-immigration-ad-was-panned-racist-turns-out-it-was-also-based-falsehood/

Trump Launches 'Racist' Ad Conflating Caravan Migrants With Convicted Cop-Murderer Days Before Midterms - Newsweek

"His dog whistle of all dog whistles is immigration. This has been Donald Trump's playbook for so long," DNC Chair Tom Perez said. ....
https://www.newsweek.com/trump-launches-racist-ad-conflating-caravan-migrants-convicted-cop-murderer-1196067

Luis Bracamontes, Cop-Killer in Trump’s Twitter Video, Actually Came Back to U.S. Under Bush - The Daily Beast

Trump also failed to mention that Bracamontes used an AR-15, a weapon that Republicans, including the president, don't want to outlaw. ....
https://www.thedailybeast.com/luis-bracamontes-cop-killer-in-trumps-twitter-video-actually-came-back-to-us-under-bush