State's Prosecutor Stephen Sedensky said 154 rounds were fired from a Bushmaster .223-caliber rifle and one bullet was fired from a Glock handgun Lanza used to kill himself Dec. 14, NBC News reported.
Some of the information from warrants and an accounting of what police recovered in Lanza's home and vehicle were released Thursday, a week before state lawmakers were to take up bipartisan reforms to Connecticut's gun laws, as well as and mental health and school safety reform.
Authorities said three samurai swords were recovered at the home that Lanza shared with his mother, Nancy Lanza, whom he killed before heading to the elementary school, where he killed 20 children and six adults before shooting himself.
Also recovered were a National Rifle Association certificate and boxes of Lanza's papers and writings, authorities said.
Police also recovered nine 30-round magazines, three of which were full, for the Bushmaster Lanza took to Sandy Hook, NBC News said.
Besides the Bushmaster XM15-E2S rifle with a 30-round magazine and the Glock 10mm handgun, authorities said they found a Sig-Sauer 9mm semiautomatic pistol in the school.
Police found a shotgun in the car Lanza drove to the school.
All of the weapons were legally owned by his mother, authorities have said.
Reports indicated Lanza was obsessed with mass killings, including the 2011 massacre in Oslo, Norway, in which 77 people died in a shooting and bomb attack.
A law enforcement official told NBC News in February Lanza collected material on mass shootings, although the official said there was no indication whether the material had a role in the school massacre.
State Senate Majority Leader Martin Looney, D-New Haven, has said next Wednesday is the date planned for a vote on a bipartisan package of gun reforms and mental health and school security legislation in the works for weeks since the Dec. 14 tragedy, the New Haven Register reported Thursday.
The bipartisan legislation is expected to include a ban on future sales of magazines with greater than 10 rounds; universal background checks stronger penalties for gun violations and new registration rules, the Register said.