Ammonium nitrate, a high-nitrogen fertiliser and ingredient used in homemade bombs was found as police searched Stephen Paddock’s car.
Clark County Sheriff Joseph Lombardo revealed the news and stated that over 16 guns were found in Paddock’s room at the Mandalay Bay Hotel.
Officers also discovered a further 18 guns, a litany of explosive called tannerite and “several thousand rounds of ammunition” at the shooters home in Mesquite, Nevada, according to Mr Lombardo.
The Sheriff revealed that “some electronic devices” were found at the gunman’s home and they are currently being evaluated.
Ammonium nitrate can be combined with other chemicals to create heinous explosives – recipes for the creation of homemade bombs can be found on the internet with ease.
Tannerite is often used as a rifle target due to the large bang and puff of smoke that ensues after contact with a bullet – the substance can also produce a deadly explosion.
A motive is yet to be found for the shooter with no prior criminal history, according to police.
Police are hoping to speak with a woman described as the “companion” of the shooter after she returns from a trip to Tokyo.
ISIS has claimed responsibility for the attack, however authorities have so far found no connection to the terror group .
At least 59 people were killed and 527 were injured in the 72-minute shooting that targeted those attending a Jason Aldean country music show along the Las Vegas Strip.
Shots were fired from the 32nd floor of the Mandalay Bay Hotel, targeting the 22,000 people attending the concert.
It took police an hour and 12 minutes from the first 911 call reporting the incident to locate Mr Paddock.
Once police breached the shooter’s room on the 32nd floor, the 64-year-old had already committed suicide.
The first shots were fired at 10.08pm PT (06.08 GMT) – the attack is deadliest mass shooting in modern US history.