The gunman who opened fire at a Reno casino on Monday fired 80 shots during a deadly rampage that left three people dead and several others injured, authorities said Tuesday, though the shooter’s motive remains unclear.

The suspect, identified as Dakota Hawver, 26, of Reno, is in critical condition after being shot by police during a gunfight outside the Grand Sierra Resort and Casino, according to the Sparks Police Department, which is leading the investigation.

Investigators have found no connection between Hawver and the Grand Sierra Resort or any of the victims, and his motive remains unknown, according to the department.

Hawver walked on foot to the valet area of the casino just before 7:30 a.m. and opened fire on a group of victims using a 9mm handgun and multiple magazines, officials said. 

When the shooting began, the suspect’s gun initially malfunctioned before he was able to get it to shoot multiple times on the group outside the casino, police said Monday. He then ran through the parking lot, where he encountered an armed security guard.

The gunman shot at the guard, who returned fire, before continuing to run, police said. The suspect eventually encountered responding police officers and was shot in an exchange of gunfire.

Authorities said the investigation is ongoing.