GAITHERSBURG, Md. — The man Aruban authorities suspect was involved in the death of his travel companion while visiting the Dutch island courted other women with his blue-green eyes, tall physique and offers of cruises and vacations, and his $1.3 million stone mansion in this upper-class Washington, D.C., suburb.

But Gary Giordano's ex-romantic interests say the allure was only surface-deep.

Giordano, 50, a self-employed businessman and twice-divorced father of three sons, has denied any wrongdoing through his attorney since the disappearance of 35-year-old Robyn Gardner, who authorities now believe is dead. Her remains have not been found, despite four days of searching the area where Giordano told officials an ocean current pulled her away as they snorkeled Aug. 2.

FBI agents combed through his Gaithersburg home Friday night, while Aruban police officers and firefighters searched an abandoned phosphate mine for clues. Nobody was seen being taken from the mine.

Giordano has told authorities that Gardner, a platinum blonde who loved tennis and running, never made it back to shore after the two became separated. The exact nature of their relationship isn't clear, and she had a boyfriend at home in Maryland. Authorities doubt certain aspects of his story, including whether the pair even went into the water, and say they're seeking witnesses to build their case against him.

His family has stayed mum during the investigation, though a close friend said he can't imagine Giordano being involved in someone's death. Court records and former romantic interests reveal a man who could by turns be charming and threatening and who's had several volatile relationships.

"He can't control his anger," his first wife, Sharon Cohen, wrote in court papers in 2001.

Giordano married Cohen in 1987, several years after earning a degree in computer science from the University of Maryland. The couple had three sons, but the relationship deteriorated until they finalized their divorce in 2003. At one point, each accused the other of abuse, with Giordano alleging his wife struck him in the back with a steel cooking spoon during a heated argument.

She countered he had a nasty temper, throwing phones, cursing and becoming violent with one of their sons.

Giordano is gregarious and fun, said Eric Curtis, a friend who said he regularly hangs out with him in restaurants and bars. He said he's never even seen Giordano raise his voice.

"He'd talk to anybody, male or female, and within minutes he'd have anybody laughing," Curtis said.

But Giordano apparently struggled with relationships after his first marriage ended. He and his second wife, whose phone rang unanswered Saturday, divorced in 2008 after two years. However, court records don't suggest an especially bitter split.

In the three years since then, other women he dated — many of them thin and blond like Gardner — found their romantic relationships with him turned ugly. One woman accused him of threatening her by saying "the world would be better off without me" and of secretly videotaping their sexual encounters.

The woman met with prosecutors, but told authorities she didn't want to pursue the case, said Montgomery County State's Attorney John McCarthy. The woman's lawyer says her client was frightened of Giordano.

She claimed in court documents that Giordano retaliated by putting revealing photos of her in neighbors' mailboxes. He claimed she had slandered him in emails and letters and requested his own restraining order.

Jeanette Farago, a former neighbor, started dating Giordano around the time of his second divorce. She said Giordano was charismatic but could become angry and possessive, though she said she never felt physically threatened. Once, he wanted to take her on a cruise but became irate when she didn't want to go, she said, a situation Gardner also found herself in, according to a friend.