Sen. Ted CruzRafael (Ted) Edward CruzCruz raises .3 million in first quarter of 2021 Boehner says he voted for Trump, didn't push back on election claims because he's retired Boehner: Trump's claims of stolen election a 'sad moment in American history' MORE (R-Texas) tweeted a letter from the Zodiac Killer in an apparent Halloween joke Wednesday.

The once-popular meme that Cruz is the Zodiac Killer emerged during the 2016 Republican presidential primary. The letter shows the Zodiac's cryptography, which he sent to newspapers during his killing spree.

ADVERTISEMENT

Five people in Northern California were killed by the Zodiac, who was never identified, in the late 1960s and early 1970s.

Cruz's wife, Heidi, denied her husband being the Zodiac killer, calling it “a lot of garbage." Cruz was born two years after the first killings.

Cruz had previously tweeted this image last year joking with Sen. Ben SasseBen SasseBipartisan lawmakers signal support for Biden cybersecurity picks To encourage innovation, Congress should pass two bills protecting important R&D tax provision Maine GOP rejects motion to censure Collins MORE (R-Neb.) about a soda that he spilled on Cruz.

The Republican senator is locked in a tight reelection campaign with Rep. Beto O'RourkeBeto O'RourkeO'Rourke clarifies remarks, leaves door open to gubernatorial bid O'Rourke says he's not planning on run for Texas governor O'Rourke slams Cruz for video of border visit MORE (D-Texas). The nonpartisan Cook Political Report rates the race a "toss-up."