KEY LARGO -- The man who has been investigators' lone suspect in the suspicious 2008 scuba diving death of his girlfriend off of Key Largo has a prior conviction for domestic violence, records newly obtained by the Free Press show.

Meanwhile, Monroe County Sheriff's Office detectives, who let their investigation of Eugene "E.B." Jackson go dormant in September 2009 after prosecutors declined to take the case, have once again begun digging, Detective Terry Smith said last week.

"If somebody has a propensity for violence, it usually doesn't go away," Smith said.

Jackson, a hotel builder from Salisbury, N.C., was the only person in the presence of girlfriend Joanne Page when she died after the couple got separated from their dive boat on Oct. 30, 2008 during a chartered excursion to French Reef.

The death of the 51-year-old Page, which seemed fairly ordinary at first, quickly became extraordinary after an autopsy revealed that Page had a series of neck injuries that were consistent with strangulation.

Monroe County Medical Examiner E. Hunt Scheuerman, M.D. would eventually rule the cause of death to be undetermined. But he says he harbors deep suspicions about the case. In April he told the Free Press that had Page died on land, he definitely would have ruled it a homicide.

Over the course of a 10-month investigation into Jackson and the Page death in late 2008 and 2009, detectives in both Monroe County and North Carolina weren't able to uncover any incidents of domestic violence between the couple. But Debby Melton, Page's sister, did go to detectives with allegations that Jackson had hit Page a couple of months before her death, giving her a black eye.

The new revelations, obtained by the Free Press, could lend credence to Melton's claim.

Jackson, 60, was convicted of assaulting ex-wife Elaine Steinmetz in September 1992, background checks show.

As a result of that assault, on Sept. 15, 1992 a judge in Cabarrus County, N.C., just north of Charlotte, granted Steinmetz's request for a restraining order against Jackson. Less than a month later Jackson was convicted of trespassing.

In her assault complaint, Steinmetz alleged that Jackson flew into a rage while holding their baby son.

"Defendant head-butted me, struck me in the mouth and jaw with his fist, shoved me against the wall, kicked me in the thigh, threatened to kill me, to take the minor child away, threatened witnesses and refused to relinquish grip on our minor child," she wrote. "I believe him capable of carrying out his threats."

Reached by the Free Press, Jackson declined to comment on his criminal record. He has previously told detectives that on that fateful 2008 dive trip he tried to save Page after he saw her floating on her back as the couple tried to make their way up current to the boat, reports say.

However, when investigators asked Jackson to take a voice stress analysis test, he declined to cooperate, reports say.

Smith, who recently learned about Jackson's domestic violence conviction, said detectives were unable to find his criminal history earlier because the cases were disposed of under an unusual North Carolina law called Prayer for Judgment, in which there is a finding of guilt, but no entry of judgment into the record.

The Prayer for Judgment provision is usually used for traffic offenses, several North Carolina law firm Web sites say.

Melton said the Prayer for Judgment explanation is not good enough.

"I continually told them that there was documentation," she said. "I told them that I do not have specific names, but being law enforcement officers they should be able to find them. It was very frustrating for me to find out that they had not even pursued that avenue."

Smith said detectives decided to probe further into the Page case after Melton visited the Keys in early June and made the case for a deeper search into Jackson's background.

State Attorney Dennis Ward has also taken a renewed interest in the case, Smith said, and has suggested that detectives look into Jackson's phone records from the time of his October 2008 Key Largo visit.

Smith said he'll take that step. But he also sounded a note of caution. Jackson's record of domestic violence is good information to have, he said, but it doesn't prove anything about the Page case and wouldn't be admissible in court.

"It doesn't change the case any," Smith said.

Ward sounded a slightly different tone.

"Maybe not yet," he said.

rsilk@keysnews.com