A doctor has admitted trying to kill a dialysis patient by removing a tube and causing the man to bleed out, police said Friday.

Internist Kenjiro Hashizume of Machida, western Tokyo, told investigators he went to his clinic and picked a victim at random after suddenly getting an urge to kill someone, officers at Machida Police Station said.

Hashizume, 49, was arrested Thursday for allegedly removing a tube that controlled the blood flow of a patient undergoing dialysis the previous day. He appeared before the Tokyo Public Prosecutor’s Office on Friday.