Which logical fallacy is used in the text?
We cannot have shorter prison sentences, even for low-level criminals. It would only be a matter of time before all prison sentences were reduced and violent offenders were roaming the streets!

 - ad hominem: an attack against the person making the argument, rather than the argument itself
 - bandwagon fallacy: the assumption that the popular choice is automatically correct
 - slippery slope fallacy: the false assumption that a small first step will lead to extreme consequences
The text argues that going easy on low-level criminals will lead to going easy on violent criminals, too. However, there is no reason why easing penalties for low-level criminals must necessarily lead to changes to penalties for violent criminals. This illustrates a type of logical fallacy known as the slippery slope fallacy.