Washington — Police have identified a suspect arrested in connection with three shootings targeting a Democratic National Committee office in Tempe, Arizona, since September.

Jeffrey Michael Kelly, 60, was also arrested for allegedly hanging suspicious bags of white power from political signs lined with razor blades in the nearby village of Ahwatukee, according to the Tempe Police Department.

Police announced the arrest Tuesday. Kelly is charged with several felonies, including committing an act of terrorism, unlawful discharge of a firearm and shooting at a non-residential structure. He is also charged with criminal damage, a misdemeanor. Police said Wednesday a public witness tip led to Kelly's arrest.

After the first two shooting incidents in September, police said there were gunshots through the office's front windows. The first incident on Sept. 16, police said, appeared to be from a BB gun or pellet gun. The second incident occurred Sept. 23 and involved about six real bullets, Tempe Police Chief Kenneth McCoy said at a news conference Wednesday night.

"No one was inside the office during the overnight hours, but this raises concerns about the safety of those who work in that building, as well as those nearby," Sgt. Ryan Cook, the police department's public information officer, said in a Sept. 24 statement.

The third incident occurred on Oct. 6, according to McCoy. A silver Toyota SUV that had been seen in surveillance footage from the second shooting was also seen on security video from the third shooting.

The office was shared with staff from Vice President Kamala Harris' campaign.

Kelly had previously been arrested in 2022 for stealing campaign signs while driving the same silver SUV, police said.

Kelly made his first court appearance Wednesday, and a judge set his bail at $500,000 and ordered electronic monitoring and house arrest in the event he is able to raise the money, Maricopa County Attorney Rachel Mitchell said.

During Wednesday's court hearing, Deputy Maricopa County Attorney Neha Bhatia said that authorities believe Kelly "was preparing to commit an act of mass casualty," and that his "progression of violence was escalating."

Bhatia said that while searching Kelly's home, agents with the Bureau of Alcohol, Tobacco and Firearms found over 120 guns and over 250,000 rounds of ammunition. Those included multiple machine guns. Silencers, scopes and body armor were also found in the home, Bhatia said.

"He had guns consistent with the guns that were used, or the weapons that they believe were used, at the shootings at the structure," Bhatia told the judge.

He also had a machine gun in his vehicle at the time of his arrest, Bhatia disclosed.