A lawsuit has been filed against the Hartford Archdiocese alleging that in the 1970s a priest assigned to churches in Bristol and Waterbury sexually abused a boy whose mother had died.

The lawsuit filed in New Haven Superior Court on behalf of Matthew Cornell names the Rev. Gregory M. Altermatt as the alleged abuser.

Cornell’s attorney, Thomas McNamara, held a press conference Wednesday to discuss the lawsuit. He said that Cornell didn’t want to file the lawsuit under a pseudonym because “he wanted (the church) to know who he was.”

McNamara said that the abuse started while Altermatt was a priest at St. Matthew Church in Bristol, which was his first assignment after being ordained as a priest in 1976.

Altermatt is currently on senior status and lives in New Haven, according to archdiocese records. His attorney, Walter Hampton, declined comment Wednesday on the lawsuit.

Archdiocese of Hartford Director of Communications Maria Zone said Wednesday the diocese would have no comment on the lawsuit, but noted the archdiocese now performs “background checks of all of its personnel who have regular contact with children and vulnerable adults.” She said it also provides “training for adults and minors that concerns sexual abuse awareness and how to deal appropriately with such issues.”

The lawsuit alleges that the abuse could have started as far back as 1976 when Cornell was 7 and Altermatt came to his home to have dinner with his parents.

The lawsuit said his parents encouraged their son to meet with the priest because of their trust in the church. Cornell’s mother died unexpectedly in 1979 and Altermatt offered to help out Cornell’s father, who also had a daughter who was disabled.

McNamara said this allowed Altermatt to spend frequent time alone with Cornell and “increase the frequency and level of abuse.”

“(Altermatt) became almost another family member especially after (Cornell’s) mother died and (Altermatt) became almost (Cornell’s) caretaker,” McNamara said.

The lawsuit alleges that Altermatt frequently abused Cornell in the rectory of St. Anne Church in Waterbury, where the priest had been reassigned, a movie theater in Waterbury, at the Cornells’ home in Bristol and in Altermatt’s mother’s condominium in Florida, where the priest once took the boy on vacation.

In 2005, the archdiocese paid out $22 million to settle sexual abuse lawsuits against 14 priests. Many of the 43 accusers who took that settlement alleged that they were abused during the 1970s.

Altmeratt wasn’t one of those priests and has never been sued for sexual abuse, according to data kept by national victims of priest abuse organizations.

McNamara said they have already filed discovery motions to try and get Altermatt’s file.

Cornell was not at the press conference. He no longer lives in Connecticut. McNamara said Cornell first brought his case to Massachusetts lawyer Mitchell Garabedian, who represented numerous victims in lawsuits against the Boston Archdiocese.

“(Cornell) held this in for all this time, but didn’t want to carry this baggage for the rest of his life,” McNamara said.