Analysis of information sources in references of the Wikipedia article "Capital punishment in Judaism" in English language version.
Similarly, the passage in Mishnah Makkot 1:10: "A Sanhedrin that puts a man to death once in seven years is called a murderous one. R. Eleazar ben Azariah says, 'Or even once in 70 years.' R. Tarfon and R. Akiva said, 'If we had been in the Sanhedrin, no death sentence would ever have been passed'; Rabban Simeon b. Gamaliel said: 'If so, they would have multiplied murderers in Israel.'
This refers to the statement in the Mishnah (Mak. 1:10; Mak. 7a) that a Sanhedrin that kills (gives the death penalty) once in seven years (R. Eleazer b. Azariah said: once in 70 years) is called "bloody" (ḥovlanit, the term "ḥovel" generally implying a type of injury in which there is blood).