Police received a call around 2:30 a.m. about a confrontation between guests at the Motel 6 at 4673 Lassen Road, police said.
Arriving officers spoke with the victim, who told them he had seen the suspect, later identified as Michael Hamby, 39, throw a small dog off a second-floor balcony, police said.
The dog landed on the ground below and was found uninjured, police said.
The victim confronted Hamby about throwing the dog, which led to an argument in which a motel clerk intervened and managed to get the two guests to return to their rooms, police said.
The victim told officers that a short time later, he heard a knock at his door and when he opened it, he found Hamby standing in the doorway. He said Hamby pointed a gun at him and then ran off, according to police.
A SWAT team of Livermore and Pleasanton police officers was called to the motel because there was a gun involved, and because Livermore police have a history with Hamby, according to police.
Hamby had been arrested by Livermore police on April 27 on suspicion of assault, child endangerment and illegal firearm possession, police said.
When the SWAT team arrived, surrounding motel rooms and nearby
businesses were evacuated.
SWAT team members entered Hamby's room but he was not inside. He was located nearby and taken into custody around 7:20 a.m., police said.
Hamby was arrested on suspicion of felony animal cruelty and was booked into the Santa Rita Jail in Dublin.
The victim told police he won't press charges for the alleged gun incident. No gun was found at the scene, police said.