GARDEN CITY, N.Y. (WPIX) -- Authorities are trying to figure out what caused a Long Island man to snap after he brutally killed his wife and two daughters, before committing suicide at a Baltimore hotel Sunday.

William Parente, 59, a real estate attorney from Garden City, killed his 58-year-old wife Betty and their two daughters, 19-year-old Stephanie and 11-year-old Catherine in the family's 10th floor room at the Sheraton Baltimore North in Towson, police confirmed Tuesday.

Parente reportedly executed the killings over a span of several hours in the afternoon. Betty and her two daughters died from blunt force trauma and asphyxiation and Parente took his own life after cutting himself with a knife, said officials.

Hotel employees made the shocking discovery Monday after the family failed to check out. Parente was found in the bathroom, while his wife and two daughters were found on the bed.

The FBI has launched a probe into Parente's investment dealings, reports say. The investigation begun after authorities received numerous complaints from investors, FBI spokesman James Margolin told Newsday.

In addition, Baltimore County police have come forward with allegations that Parente may be involved in questionable financial dealings. Parente was reportedly unable to return hundreds of thousands of dollars to one investor and two checks he wrote to a Bayside lawyer, for over $200,000, bounced.

Police did not reveal if Parente suffered from any mental heath problems.

The family was in Baltimore visiting Stephanie at Loyola College, like they have done many times in the past. They were last spotted eating breakfast together on Sunday morning.

Students at Loyola College held a mass for Stephanie Tuesday as the news of her death shocked many on campus.

"I still can't even get my head around it," said Collin Wheeler, a sophomore who attended the Mass. "I just feel really hopeless."