Mexico backsliding on the death penalty?

Mexico's congress has agreed to debate reinstating capital punishment in response to a recent crime wave. But fortunately that's as far as this knee-jerk response from paniced, scared people is likely to get - firstly, because Mexico's ban on the death penalty is entrenched in its constitution and would require a constitutional amendment to remove, and secondly because Mexico is a party to the Second Optional Protocol to the International Covenant on Civil and Political Rights, a binding human rights instrument banning the death penalty which has no exit clause. So, even if they want to, they can't - or at least not without significantly undermining their international standing and making it clear that their signature on a treaty isn't worth squat. OTOH, the latter hasn't stopped Liberia...