Well, she didn't use the word "ninjas" exactly, but she did say that two masked intruders sneaked into Alexander's home and attacked them both while they were in the shower. And when asked why she didn't report the ninjas to the police after they had slit her lover's throat, she replied, "I've grown up around gangs and you don't snitch." Even though it's entirely plausible that criminal organizations such as the Foot Clan adhere to strict codes of omerta, zero point zero people believed her (as any actual ninja assassination would be impossible to notice).
So after the masked intruder story fell apart quicker than a wet pancake, Arias coughed up 10 different letters allegedly written by her ex (who was now suddenly a pedophile). One conveniently admitted to hitting her in the face, another claimed he wanted to marry her so he could eliminate his "deviant thoughts," and another asked her to wear boy's underwear so he could rip them off. Shockingly, the judge threw the letters out of court.
Arias responded by claiming her ex had "oodles of cancer" that she was merely removing via "knife-o-therapy."