(CNN) — The suspect in a string of shootings in Mesa, Arizona, which killed one man and wounded five others, is a convicted felon who was out on probation.
Ryan Elliot Giroux has been to prison twice for felonies, including an attempt to commit aggravated assault.
The 41-year-old was sentenced to seven years and six months behind bars in July 2007, but was released in October 2013. His probation runs through October 2016.
The Mesa Police Department said it was questioning Giroux on Wednesday evening, but by early Thursday, he had not been charged or booked into jail.
Police are looking for a motive in the shootings that began at the Tri-City Inn.
The first shots were fired after the suspect got into an argument with three people that he likely knew, according to Detective Esteban Flores.
One man who was shot at the Tri-City Inn died, Flores said. The motel is across the street from the East Valley Institute of Technology.
Two women also were wounded outside the motel. A fourth victim, an EVIT student, was shot at a restaurant run by the school, Flores said.
As the shooting rampage unfolded, the suspect carjacked a Honda and later shot a man after breaking into his apartment, according to police. Another man in an apartment complex next door was also shot. Both men were expected to live. Flores said the suspect was probably trying to rob his victims as he tried to get away from authorities.
Flores said the suspect was found by Mesa’s SWAT team in a vacant second-floor condo. Police used a Taser stun gun to subdue him.
Charges are expected to be filed against Giroux on Thursday, Flores said.
An Arizona Department of Correction’s photo shows a heavily tattooed Giroux.
“Skin” and “head” are tattooed over his eyebrows. The number 88 is on his left temple, with additional ink on his chin and neck.
“Obviously he has tattoos on his neck and his face, his forehead,” Flores said. “Those are typical tattoos that you do see sometimes on white supremacists, but we don’t know if that has anything to do with what happened today.”
Neo-Nazis use the number 88 as an abbreviation for “Heil Hitler.” H is the eighth letter in the alphabet, so the Nazi salute becomes 88 in shorthand.
Flores said he believes all of the shooting victims were white, with one being white and of Hispanic descent.
“I have no information that his (Giroux’s) affiliations or beliefs had anything to do with what occurred today,” Flores said.
News of the shootings caught the attention of the state’s senior U.S. senator.
“My thoughts and prayers are with the victims and families impacted by the tragedy in Mesa today,” U.S. Sen. John McCain said in a statement. “Our deepest thanks are with the Valley police and first responders who assisted the victims and tracked down the perpetrator to bring this dangerous situation to an end.”
Mesa is about 20 miles east of Phoenix and is Arizona’s third-largest city.
CNN’s Stephanie Elam, Amanda Watts, Steve Almasy, Jason Hanna, Tina Burnside and Tony Marco contributed to this report.