(CNN) — The Connecticut State Police on Friday will release its report on the Sandy Hook Elementary School shootings, according to a state police spokesman.
The report, several thousand pages long, contains text, photos and 911 calls from the day of the shootings, said the spokesman, Lt. J. Paul Vance. The report "has been redacted according to law."
Earlier this month, authorities released audio recordings of 911 calls from the day of the second-deadliest shooting in U.S. history. The recordings offered a glimpse into the horror at Sandy Hook Elementary School.
Last month, prosecutors issued a summary of the investigation that described gunman Adam Lanza as obsessed with mass murders, but concluded that Lanza's motives for the massacre might never be known.
Lanza, 20, killed 20 first-graders and six school staff members with a semi-automatic rifle at the elementary school on December 14, 2012. Earlier, he killed his mother inside their home. Lanza -- who had "significant mental health issues, according to the report -- committed suicide with a handgun as police arrived.