Spear, 29, and Thomas Henry Berry, 39, were killed in front of their 5-year-old daughter on an isolated stretch of highway near Puerto Cabello Monday night during a robbery.
On Thursday, Commissioner Jose Gregorio Sierralta said the discovery of a digital camera during a search of the home of one of the people arrested for their killing played a major key in the investigation.
The camera led police to a criminal band that preyed on motorists on the section of the highway near Puerto Cabello.
According to local media reports, Spear and Berry had a good relationship despite being divorced, and were returning to Caracas on vacation when a sharp object in the road punctured two of their tires.
After their car was damaged, officials said two tow trucks arrived almost immediately, and the attack occurred after the car had been lifted onto one of the trucks. When the family locked themselves in the car, police said the assailants fired at least six shots.
The crew of one of the tow trucks helped lead police to the people arrested.
Spear's death triggered a national uproar over Venezuela's rampant violent crime. The country has one of the world's highest murder rates, even causing people to stay home after dark.
According to the nonprofit Venezuelan Observatory of Violence, the South American country's murder rate was 79 per 100,000 inhabitants last year. Government statistics put the rate lower.
The couple's slaying followed a pattern of late-night assaults carried out by disabling cars with obstacles placed on roadways.
Sierralta told local reporters that the criminal band was led by a 32-year-old ringleader known as "Fat Danilo". At least 11 people, including a 19-year-old, took part in the shooting and four remained fugitives.
The ringleader allegedly supplied the other men with guns and drugs.
The slain couples' families held a private wake Thursday, and said they would later open the viewing to the public. Spear and Berry were to be buried Friday.
Spear was crowned Miss Venezuela in 2004.
The Associated Press contributed to this report.