The Las Vegas Police Department on Friday concluded its investigation into the mass shooting at the Route 91 Harvest festival, which claimed the lives of 58 people and left more than 800 injured.

The final report produced by the department provides a detailed timeline of law enforcement’s response to the attack, explains its investigative efforts, and includes an autopsy of the gunman, who took his life in his hotel room on the 32nd floor of the Mandalay Bay Hotel, the vantage point from which he launched his assault on concertgoers below.

Crucially, the report also includes a detailed accounting and forensic analysis of the significant arsenal recovered from the gunman’s hotel room. In total, the police recovered 18 rifles and a handgun. Thirteen rifles were outfitted with bump stocks, the aftermarket devices that allow semiautomatic weapons to mimic the rate of fire of an automatic rifle.

A forensic firearms report performed by investigators shows further that the gunman used all but one of those bump stock-equipped rifles during his deadly attack. With the aid of the devices, the gunman unleashed a total of 1,049 rounds at the crowd below. The assault lasted just 11 minutes.

While it was widely known that police recovered bump stocks on the scene, the report is the first to detail the extent of their use in the catastrophic shooting.

Following the Las Vegas shooting, which remains the deadliest mass shooting in American history, political figures from both parties expressed alarm at the easy availability of bump stocks.

Eight states have since passed laws banning or restricting the devices. The Bureau of Alcohol, Tobacco, Firearms and Explosives, announced in December that it would consider reclassifying the bump stocks as machine guns, effectively barring them from civilian ownership.

The report produced by the LVPD states that the gunman was not prohibited from owning firearms, and lawfully acquired all the weapons he used in the attack.

Even if the gunman had a criminal record, he would have been able to purchase bump stocks: In the states where the devices remain unregulated, they are classified as accessories, and do not require a background check.

You can read the LVPD’s full report here:

-Additional reporting by Alex Yablon