Walton County Assistant District Attorney Eric Crawford says 27-year-old Joseph Pallipurath gave a videotaped confession on Tuesday, hours after he was arrested at a motel 40 miles east of Atlanta.
Crawford says Pallipurath told investigators he would have killed everyone in the church if he'd had a machine gun.
Pallipurath told authorities he was unhappy that church members were blocking his attempts to contact his wife, who had left him three months ago.
Pallipurath had been renting a room a few miles away for two weeks beforehand, authorities said Tuesday.
He will soon return to New Jersey after waiving his right to extradition in Georgia, where he wasat a motel.
He is suspected of shooting and killing his wife, 24-year-old Reshma James, inside the St. Thomas Syrian Orthodox Knanaya Church in Clifton, a suburb about 15 miles west of Manhattan. Also killed was Dennis John Mallosseril, who maintained the church's Web site. Witnesses said he tried to intervene and break up the rampage.
A third person, James' 47-year-old cousin, Silvy Perincheril, was shot in the head and remains hospitalized in critical condition. James had taken out a restraining order against Pallipurath, prosecutors said.
Pallipurath was arrested Monday night in Monroe, about 40 miles east of Atlanta, after police received a tip that he was in the area. A motel clerk recognized his face from a photograph.
Pallipurath appeared in court wearing a blue jail jumpsuit and shackles and only answered "yes" and "no" when the judge asked him questions about his charges and extradition process. He had no attorney.
Georgia authorities said they would arrange his return to New Jersey within the next 10 days.
According to NorthJersey.com, police found two guns in a trash can near Pallipurath's abandoned Jeep, which authorities located Tuesday in a shopping center parking lot in Clifton.
In New Jersey, Passaic County Prosecutor James Avigliano gave new details Tuesday morning about Pallipurath's path leading up to the slayings.
After fleeing three months ago from what relatives said was an abusive, arranged marriage in California, James came to New Jersey and stayed with Perincheril, her cousin who lives in Hawthorne.
"She found out he wasn't all he was cut out to be," Avigliano said. "He was abusive toward her, and she left him and came out here."
The couple were married just over a year ago in India and moved to Sacramento in January.
Reshma's aunt Maria Joseph, of Hartford, Conn., said she warned her niece, who was studying to become a nurse, not to marry him. Other relatives told her the man had a history of "behavioral problems," Joseph said.
Mathai Pallipurath, the suspect's father, said he thought his son and daughter-in-law were happy together, and he described his son as "handsome" and "a nice guy."
According to a published report, however, the elder Pallipurath was granted a restraining order against his son in May. The father said Joseph was abusive to family members and had threatened his life.
In the story posted on its Web site Monday, The Sacramento Bee, citing family court records, said the restraining order was dropped at Mathai Pallipurath's request on June 17. Mathai Pallipurath was not available later Monday to comment on the report. A man who answered the phone at the family's Sacramento home Monday evening said he did not wish to speak further.
The shootings have reverberated throughout the Knanaya faith, a close-knit Christian minority in India who are even closer-knit in the United States.
The parish priest, Rev. Thomas Abraham, said he heard a loud noise and thought something had fallen in the church. He got up to go toward the noise, only to be hit with a wave of parishioners pushing him backward, saying someone was shooting inside the sanctuary.
He said church members were in shock.
"They're all scared; they're all really upset," he said. "We have to hold together in this time of adversity."