Tommy K. Wong, 52, was killed during a robbery at Capital Jewelers. Police released a video of a suspect in the killing who entered the store wearing a traffic safety vest. Police said the man was inside the store for less than 20 minutes and that he took jewelry.
Caroline is being held without bond at the Arlington County Detention Facility, police said.
Dustin Sternbeck, a county police spokesman, declined to say how detectives identified Caroline.
“The detectives worked around the clock to locate this individual, and using various methods, they were able to identify him,” Sternbeck said.
Authorities declined to release additional information about the case, including how Wong was killed, because charges were pending against Caroline.
D.C. police and the FBI helped county police arrest Caroline, Arlington authorities said.
Online court records in the District, Maryland and Virginia indicate that Caroline has a record of arrests for crimes including larceny, credit-card fraud and failing to appear in court. A week before Wong was killed, Caroline was charged in Arlington with failing to obey a traffic signal.
In Virginia, a slaying that occurs during a robbery can be charged as a capital offense and could result in the death penalty.
Wong, who lived in Herndon, was found dead inside the locked store shortly before midnight Friday. Family members contacted police because he had not returned home.
Relatives remembered him as a dedicated family man who was kind and generous to his friends.
The Wong slaying was the second in the county this year. It came days after a man killed his wife and then himself near Fairlington. That marked Arlington’s first homicide since March 2010.
Josh White and Jennifer Jenkins contributed to this report.