The man accused of killing three people in attacks at Jewish-related sites in Kansas is a well-known white supremacist who has run for public office on a white power platform and was once the subject of a nationwide manhunt.
Frazier Glenn Cross was booked into Johnson County jail on a preliminary charge of first-degree murder.
At a news conference, Overland Park police chief John Douglass declined to publicly identify the suspect, but a jail official identified him as 73-year-old Cross.
"Today is a sad and very tragic day," Mr Douglass said.
According to police, the attacks on Sunday happened within minutes of one another.
A gunman opened fire on two people in the car park behind the Jewish Community Centre of Greater Kansas City. He then drove a few streets away to a Jewish retirement community, Village Shalom, and gunned down a woman or girl there, Mr Douglass said. Officers arrested the suspect in a school car park a short time later.
Authorities declined to release the victims' names pending notification of their relatives, but the family of the first two victims released a statement identifying them as Dr William Lewis Corporon, who died at the scene, and his 14-year-old grandson, Reat Griffin Underwood, who died at Overland Park Regional Medical Centre.
They were both Christian and the family thanked members of their church congregation, among others, for their support.
"We take comfort knowing they are together in Heaven," the family said.
Rebecca Sturtevant, a hospital spokeswoman, said family members said Dr Corporon took his grandson to the community centre so that the boy could try out for a singing competition.
Mr Douglass said the suspect made several statements to police "but it's too early to tell you what he may or may not have said". He also said it was too early in the investigation to determine whether there was an anti-Semitic motive for the attacks or if they will be investigated as hate crimes. The Jewish festival of Passover begins on Monday.
"We are investigating it as a hate crime. We're investigating it as a criminal act. We haven't ruled out anything," he said.
Although the suspect was booked under the last name Cross, he is probably better known as Frazier Glenn Miller. A public records search shows he has used both names, but he refers to himself on his website as Glenn Miller and went by the name Frazier Glenn Miller in 2006 and 2010 campaigns for public office.
The Southern Poverty Law Centre, which tracks hate groups, said it reached Miller's wife, Marge, by phone and that she said authorities had been to their home and told her that her husband had been arrested over Sunday's attacks.
According to the law centre, Miller has been involved in the white supremacist movement for most of his life. He founded the Carolina Knights of the Ku Klux Klan and was its "grand dragon" in the 1980s before the centre sued him for operating an illegal paramilitary organisation and using intimidation tactics against blacks. He later founded another white supremacist group, the White Patriot Party.
Miller, an army veteran and retired truck driver, was the subject of a nationwide manhunt in 1987 after he violated the terms of his bond while appealing against a North Carolina conviction for operating a paramilitary camp. The search ended after federal agents found Miller and three other men in a mobile home filled with hand grenades, automatic weapons and thousands of rounds of ammunition.
Miller tried running for the US House in 2006 and the US Senate in 2010.
President Barack Obama released a statement expressing his grief over the attack.
Israeli prime minister Benjamin Netanyahu gave his condolences to the families of the victims.
"We are condemning the murder which according to all signs was committed because of hatred of Jews," Mr Netanyahu said in a statement. "The state of Israel ... together with all civilised peoples is committed to fighting against this plague."