The girlfriend of a man arrested on Tuesday in a shooting that wounded three women of Asian descent in a hair salon in Dallas’ Koreatown told police he has delusions that Asian Americans are trying to harm him, an arrest warrant affidavit states.

Jeremy Smith faces three charges of aggravated assault with a deadly weapon, police said. Smith is being held on a 300,000 dollar (£240,270) bond, according to jail records that do not list a lawyer for him. In public records, his age is listed as both 36 and 37.

When asked if he considered the shooting an issue of racism, mental health or both, Dallas police chief Eddie Garcia said it was too early to tell.

“Right now, it’s an issue of hate. It’s a hate crime. However that manifests itself, I’m not here to say that. I can tell you that I know our community sees it as a hate crime. I see it as a hate crime and so do our men and women,” Mr Garcia said at a news conference on Tuesday afternoon.

Earlier on Tuesday, the FBI said it has opened a federal hate crime investigation along with federal prosecutors in Texas and the US Department of Justice’s civil rights division.

Police have said the shooting last Wednesday at Hair World Salon might be connected to two previous drive-by shootings at businesses run by Asian Americans. But Mr Garcia said on Tuesday that police are still investigating whether Smith, who is Black, was involved. The description of the suspect’s vehicle was similar in all three shootings.

According to the affidavit, Smith’s girlfriend told detectives he had been delusional about Asian Americans since being involved in a car crash two years ago with a man of Asian descent. She said he had been admitted to several mental health facilities because of the delusions.

Whenever Smith is around an Asian American, “he begins having delusions that the Asian mob is after him or attempting to harm him”, his girlfriend told police. She said he was fired for “verbally attacking” his boss, who was of Asian descent.

Mr Garcia declined to comment on whether Smith has been diagnosed with a mental illness or whether he legally obtained the gun used in the shooting, saying both questions are still being investigated.

The shooting in Dallas occurred a few days before a white gunman killed 10 Black people on Saturday at a supermarket in Buffalo, New York, and a gunman who authorities said was motivated by political hatred for Taiwan killed one person and wounded five on Sunday at a southern California church where mostly elderly Taiwanese parishioners had gathered.

Anti-Asian violence has risen sharply in recent years amid the pandemic of Covid-19, which was first reported in the Chinese city of Wuhan.