The Calhoun College junior accused this summer of keeping a cache of illegal weapons and bomb-making materials in his bedroom in the Beta Theta Pi fraternity house will plead not guilty to the charges, his attorney said this week.

David Light ’09 is facing dozens of counts of weapons and bomb-making charges stemming from an incident inside Beta this summer when Light allegedly fired a handgun after a night of partying and beer pong. A subsequent search of his bedroom turned up several illegal assault weapons and a supply of chemicals and materials commonly used for bomb making, the police said.

Over the course of the summer, Light has been in jail twice, posted a total of $400,000 in bail and, at least in part, caused Beta to be expelled from its national fraternity organization. He could now face years in prison stemming from the weapons and bomb-making charges if found guilty.

Light, 21, of Woodland Park, Colo., remains under an emergency suspension from the University pending a hearing before the Executive Committee, the University’s disciplinary body.

“Hopefully, when emotions have subsided, people will be able to take a step back and recognize that all the guns were purchased legally,” Dow said in an interview this week. “It was and is legal in Colorado to possess these guns and the problem really evolved from a lack of understanding of the inconsistencies between Connecticut law and Colorado law.”

The police said two of the guns found in Light’s room, including an AK-47, are considered assault rifles under Connecticut law. Possession of an assault rifle in Connecticut is a class D felony and, in most cases, carries a one-year mandatory minimum prison sentence.

In total, Light has been charged with 23 counts of possession of armor-piercing ammunition, 13 counts of reckless endangerment in the first degree, nine counts of breach of peace in the second degree, two counts of illegal possession of assault rifles and one count each of criminal attempt to commit the manufacture of bombs, manufacture or storage of explosive material near property of another, unlawful discharge of a firearm and threatening in the second degree.

Light was first arrested late on July 16 after he arrived home at Beta to find the police searching his bedroom and holding a warrant for his arrest. A visitor to the fraternity had reported to police that after a night of drinking the week before, Light had fired a handgun in the fraternity’s living room and, when questioned about the safety of firing the gun, said it was loaded with blanks and added “Why don’t I point it at your head to find out?”

In Light’s bedroom at 36 Lynwood Place, the police found an AK-47, an AR-15 assault rifle, a .50-caliber sniper rifle, a Russian M-91 infantry rifle, a 12-gauge shotgun, several pistols and four to five thousand rounds of mixed ammunition, the police said.

During the raid, the authorities evacuated the fraternity house after finding chemicals in Light’s room, one of which burned the hand of a YPD officer and caused him to be hospitalized. Last week, Light was again taken into custody on a series of bomb-making charges after police recovered from his computer several e-mail exchanges in which Light appears to brag about his military-style weapons and his fondness for playing with chemicals to create explosions.

The e-mails were detailed in a police affidavit obtained from Light’s case file at New Haven Superior Court.

“I may be crazy,” he wrote to a friend in February, “but I try not to be too stupid and stay out of jail.”

In the messages, Light talked of his plans to dump pounds of chemicals into the New Haven Harbor to create a “fireball” and “smoky awesomeness” [sic]. The explosion, he wrote, was “gonna be friggin amazing.”

Light also sent other e-mails, including some to other Yale students, about his plans to create different chemical explosives and about the .50-caliber “anti-tank rifle” that he was “sooo [sic] excited” his parents were buying him for his birthday. His mother only hesitated, Light wrote to a friend, when a package of “tank shells” for the gun arrived at their home. “My mom saw them and was like … Can we reverse the order?!” Light told the friend.

“It was pretty funny,” he said.

The affidavit quoted Light’s e-mails selectively and did not provide significant context for the choice quotations that appear incriminating. Dow suggested Light may have been joking or exaggerating in some of the conversations quoted by the authorities.

“The lesson from this is e-mails can be read out of context and interpreted grossly incorrectly,” Dow said. “That’s a lesson for students at Yale University and captains of industry.”

At Yale, Light was president of Chabad at Yale, a Jewish student group. Students described him as an avid gun collector, and he was a member of the New Haven Sportsman’s Club in nearby Guilford. On his Facebook profile, which was taken down shortly after his arrest, Light listed pyrotechnics, weaponry and firearms among his interests.

He was described by students as a top-notch science student who took advanced classes in chemistry and biology. Before his arrest, he had worked intermittently at Guilford-based RainDance Technologies, a nanotechnology start-up, researching market opportunities and recruiting investors. In 2005, Light worked in the Center for High Technology Materials at the University of New Mexico, focusing on microchip research.

Light was also a member of Beta, although his arrest spurred the national Beta Theta Pi organization to vote to disband its Yale chapter earlier this month. The chapter has vowed to stay open as a local, independent fraternity.

Light, meanwhile, is next due in court on Sept. 25.