CHESHIRE, Conn. -- In the wake of a deadly home invasion that left a mother and two daughters dead, residents across the state and country are asking why anyone would commit such deadly crimes.

Joshua Komisarjevsky, 26, of Cheshire and Steven Hayes, 44, of Winsted are charged with breaking into the Cheshire home of prominent doctor William Petit Jr. and holding his family hostage for hours before setting the home on fire and trying to flee.

The medical examiner ruled that Jennifer Hawke-Petit, 48, died of asphyxiation due to strangulation, and the couple's two daughters -- Hayley, 17, and Michaela, 11 -- died due to smoke inhalation. All three deaths were ruled homicides.

While very few questions had definitive answers in the days following the crime, a criminal psychologist discussed the case with Eyewitness News.

Both Komisarjevsky and Hayes have long criminal records that include larceny, burglary and drug charges, and were out on parole at the time of the Cheshire homicides.

The pair was arraigned Tuesday in Meriden Superior Court and charged with aggravated sexual assault, assault, arson, robbery, kidnapping, risk of injury to children and larceny. State police said more charges are pending.

Dr. James Monahan, a professor of criminal justice, told Eyewitness News that he believes that drugs such as cocaine or meth could have played a role in the crimes.

"Those kind of drugs are associated with superhuman, ultra-violent actions," he said.

Monahan said that the age difference between the two men is also significant.

"An older con taking the young one under his wing and teaching him the ropes," he said.

Monahan said that much like the case of the Washington D.C. snipers, Komisarjevsky and Hayes made a deadly pair and neither had a violent history.

"They didn't have much of a criminal history at all (the snipers), but they paired up and became super-violent … in a way that if you separated them, you wouldn't have seen," he said.

Police have not yet said why they suspect that Komisarjevsky and Hayes may have targeted the Petits.

Monahan said that because Komisarjevsky lived near the Petits Sorghum Mill Drive home, he may have targeted one of the Petits' daughters.

"Some sort of interest -- physically, jealousy for affluence status," Monahan said.

Monahan said that even if the Petits were random targets, he doesn't believe that the home invaders had a plan.

"Something frightened them -- kind of panic to trash and burn, covering up their tracks or evidence," he said.

Click here to e-mail news tips to Eyewitness News, or dial: 866-289-0333. Refresh WFSB.com often and watch Channel 3 Eyewitness News for the latest news updates.