Stephen Paddock's Brother Bruce Threatened to Kill Adversary

Stephen Paddock's brother threatened to kill a friend ... according to legal docs.

Bruce Paddock was a squatter in a San Fernando Valley home in 2014. He was in a feud with a guy named Hector Cruz, the property owner. According to docs, Bruce had been tampering with machinery and equipment, and the renter of the property complained to Cruz.

When Cruz confronted Bruce, according to docs Bruce adopted an aggressive stance, clenched his fists and said, "If you keep f****** with me, I am going to kill you and drop you in the desert."

And there was another incident, where Bruce allegedly approached Cruz and said, "Hit me like a man," and then Bruce punched him forcefully in the arm.

Cruz wrote in legal docs, "I am extremely afraid of Paddock, who has intimidated me by his violent character and destruction of my business office and my service bay."

Cruz also said Bruce was a habitual drug user and seller who used meth and weed, and his behavior is "extremely erratic and unpredictable."