A more perfect death penalty in Massachusetts?

The introduction by Massachusetts Governor Mitt Romney of a bill to bring capital punishment back to the state (first discussed here) may serve as an interesting test case for what arguments drive support and opposition to the death penalty.  An AP story here reports that "a day after unveiling a death penalty bill he says will make it virtually impossible to execute the innocent, Romney told reporters safeguards in the legislation are already swaying some lawmakers."  That article suggests that, at least for some legislators, concerns about mistakes and not basic moral opposition to state killing is key.  Meanwhile, this Boston Globe story spotlights the impact of both national and state politics on the development and fate of Romney's bill.

Gideon at the Connecticut Law Blog does a terrific job summarizing and analyzing key elements of Romney's proposal in this post.  But Gideon does not discuss what for me are the biggest practical issues: cost and relative efficacy.  New York has spent nearly $200 million on its death penalty system over the past decade without a single execution, and the Massachusetts system likely could expect to have a similar cost profile.  Though there is a robust debate over whether the death penalty saves lives, I have to think Massachusetts could have a much bigger impact on crime by putting $20 million each year into more police on the streets or investing in other social services. 

Consider also the fact that, according to statistics I found on the web, almost twice as many people are killed in Massachusetts by drunk drivers than by murderers, and the data on rape and other violent crimes suggest that Romney's bill may distract from more pressing criminal justice issues in Massachusetts.

UPDATE: Gideon has updated his post to review some of the capital cost issues and to provide interesting crime numbers in Connecticut (and I would also add that statistics show Connecticut, like Massachusetts, loses many more lives to drunk drivers than to murderers).  Gideon's expanded post provides great links to important discussions of the costs of the death penalty, most notably this recent testimony by the DPIC's Richard Dieter.  Now, if only Gideon or someone else might guestimate how much money has been spent in all the wrangling over the Michael Ross case.