On Saturday, a St. Charles County deputy chased a carjacking suspect in St. Louis after being rammed by that suspect, authorities say. The chase ended in the deaths of two men in their 20s who were fleeing from the deputy and shooting at him.

The deputy, who lives in the St. Louis area, was heading to the St. Louis city jail about 7 p.m. to transport an inmate back to St. Charles County, police say. He tried to stop the carjacking suspects after hearing a description of their car over his police radio. The carjacking at gunpoint occurred at 6:40 p.m. in the 1000 block of Neville Walk, near Dellwood.

Shots were fired at the deputy by one of two men inside a Chevy Cobalt, which led the deputy to Interstate 70. The Cobalt, speeding the wrong way in the westbound lanes of Interstate 70, crashed head-on with a Pontiac Grand Prix, which, coincidentally–also was stolen.

The two men in the Cobalt–brothers Anthony, 23, and Darrell Thomas, 22, both of Hazelwood–were killed instantly. Four male teenagers–15 to 18 years old–in the Pontiac were taken to a hospital for treatment. Their conditions ranged from serious to critical.

The deputy suffered minor injuries from being rammed by the suspects, police said, and was taken to a hospital for evaluation.

Sheriff Tom Neer said today the department’s policy is similar to other St. Louis area departments in that the need to chase in order arrest someone should outweigh dangers caused by that pursuit.

However, unlike other departments, Neer said, the policy does not restrict vehicle pursuits of those suspected of committing a felony.

Deputies are allowed to chase drivers suspected of committing any crime, Neer said.

St. Louis County and St. Louis city police also joined the chase on Saturday. Police said all officers backed off after the Cobalt entered the interstate heading in the wrong direction.

St. Louis city and county have similar, if not identical, policies, which require that the need to apprehend a violator outweighs hazards caused by chasing, that the suspect was attempting to commit a felony and that fleeing suspects will cause death or serious injury if their arrests are delayed in any way.

In April 2007, the U.S. Supreme Court ruled that police may use deadly force to stop a fleeing motorist who ignores warnings and poses a danger to the public. In St. Louis, after years of public outcry, the St. Louis Area Police Chiefs Association in 2006 urged the region’s departments to adopt policies that limit pursuits to times when the danger presented by the fleeing driver outweighs the danger of the pursuit itself.

Justice Antonin Scalia wrote in the court’s opinion: “We are loath to lay down a rule requiring the police to allow fleeing suspects to get away whenever they drive so recklessly that they put other people’s lives at risk.”

Could the fatal crash have been avoided had police backed off their pursuit, or did the deputy choose wisely in chasing the suspect? Should the sheriff’s department and other police departments revise their policies for chasing fleeing criminals so as not to further endanger innocent drivers?