HARTFORD, CT — Connecticut Attorney General Richard Blumenthal wants Craigslist to clean up its act or face financial penalties.He also wants to institute a program that offers financial incentives to consumers who inform on the site’s perceived misdeeds.

In a letter sent to Craigslist and the media on Wednesday, Blumenthal asked craigslist to take immediate action to combat what he called “persistent prostitution and pornography” on the website. Among Blumenthal’s proposals are the elimination of photographs in the “Erotic Services” section of the site, hiring staff to screen for ads and images that violate the site’s terms of service, charging significant fees to the credit cards of users who post ads in the Erotic Services section, blocking search terms that clearly are associated with adult entertainment and financially rewarding users who point out improper ads.

“These signature steps can stop ads that lead to horrific brutal tragedy such as the Boston murder [of masseuse Julissa Brisman on April 14], as well as other violent crime, human trafficking or exploitation of children,” Blumenthal said.

Blumenthal’s call to action came in the wake of a third killing linked to the online classified ads service. Brisman, 26, was shot to death in a posh Boston hotel, presumably by a client who booked her services as a masseuse through her ad on Craigslist. Police have charged 23-year-old medical student Philip Markoff with the murder. Markoff also stands accused of robbing another woman whose services he engaged via Craigslist.

Earlier in April, 20-year-old Michael John Anderson was sentenced to life in prison without the possibility of parole after his conviction for the October 2007 murder of a 24-year-old Minnesota woman who responded to a phony Craigslist ad seeking a babysitter.

Last year, Blumenthal spearheaded a group of 40 state attorneys general in a move to clean up Craigslist. In November, the website and the AGs signed an agreement that requires Craigslist to collect personally identifiable information, including credit card numbers, from people who post Erotic Services ads, cooperate with law enforcement and the National Center for Missing and Exploited Children, and sue software developers who help miscreants circumvent the site’s anti-child-porn security measures.

Craigslist also agreed to deploy search technology it developed to assist law enforcement in identifying missing persons, children and victims of human trafficking, and to explore technology to block inappropriate image uploads and better filters for code words and euphemisms for illegal activity.

Brisman’s murder indicates the measures are not enough, Blumenthal said.

“Craigslist has the means — and moral obligation — to stop the pimping and prostituting in plain sight,” Blumenthal said in Wednesday’s letter. “Like any bricks-and-mortar establishment, Craigslist has the responsibility and power to prohibit prostitution, pornography and inappropriate behavior on its premises.

“My proposals are feasible and affordable — including readily available new technology to block pornography and screen out prostitutes, along with financial penalties and incentive payments,” he added. “Requiring telephone numbers and credit card charges for erotic services ads were good steps, but not sufficient. Pornography and prostitutes have diminished, but hardly disappeared — an un-endangered species alarmingly alive and well in Craigslist’s Erotic Services section.

Blumenthal said he anticipates Craigslist will cooperate.

Other states and municipalities await Craigslist’s response. Dozens of prostitution and other criminal cases reside on court dockets nationwide based on arrests made with the assistance of Craigslist. Nevertheless, at least one law enforcement agency is suing the advertising service in an effort to put a stop to ads it considers illegal. In early March, Cook County Illinois Sheriff Tom Dart filed a federal lawsuit seeking removal of the site’s Erotic Services section.