1. To adopt measures for preventing the commission of crime;

2. To exclude the offender from all hope of escape;

3. To insure a trial with as little delay as is consistent with the ends of justice;

4. To bring to the investigation of each offense on the trial all the evidence tending to produce conviction or acquittal;

5. To insure a fair and impartial trial; and

6. The certain execution of the sentence of the law when declared.

Acts 1965, 59th Leg., vol. 2, p. 317, ch. 722.