Guilty plea due in wrongful conviction

“When you convict the wrong person, the real criminal remains on the street committing crimes,’’ said Howard Friedman, a civil rights lawyer representing Powell. “More women were raped.’’

Dixon’s lawyer, Veronica J. White, confirmed yesterday in a phone interview that her client would plead guilty today to a number of charges, including aggravated rape.

Powell maintained his innocence during his trial and incarceration, but Massachusetts makes it difficult for convicts attempting to prove they had not committed the crime.

“If you think that an innocent person cannot be convicted of a crime in Massachusetts, you are fooling yourself; it happened to me,’’ Powell said in a statement. “There are innocent people in prison … right now.’’

Massachusetts and Oklahoma are the only states without laws to provide convicts with access to DNA evidence and testing that could prove their innocence, and Massachusetts is the only state that does not require preservation of DNA evidence for future testing, said Gretchen Bennett, executive director of the New England Innocence Project, a nonprofit organization that provides free legal aid.

“We’re dead last in these issues,’’ Bennett said in a phone interview. “In this case, it was just luck that the evidence still existed, and eventually a number of people and lawyers working together were able to find the evidence and get access to it. This led to Anthony’s exoneration and the identification of the real perpetrator, who had gone on to commit more rapes while Anthony was in prison.’’

Postconviction DNA testing has exonerated 272 people nationwide, including nine in Massachusetts, Bennett said, since testing began in the late 1980s. The average amount of time an innocent person had spent behind bars was 12 years.

Bennett hopes Powell’s case will call attention to a bill to be debated soon in the State House.

The bill, sponsored by state Senator Cynthia Stone Creem, a Newton Democrat, and state Representative John V. Fernandes, a Milford Democrat, would require the state to maintain DNA evidence and give convicts easier access to DNA testing that could prove their innocence.