A Ciudad Juarez municipal police department operations coordinator and his wife were gunned down while driving through the Mexican border city, a police spokesman said.

Jose Portillo Hernandez and his wife, whose name has not been released, were killed on Tuesday, municipal police department spokesman Adrian Sanchez said.

Portillo had emerged unscathed from an attempt on his life earlier this week in Ciudad Juarez, a gritty border metropolis located across the Rio Grande from El Paso, Texas, where more than 900 people have died in drug-related violence this year.

Portillo's body was in the driver's seat of his vehicle, while his wife's body was found in the avenue, indicating that she tried to run away and was shot dead, investigators said.

Nearly 20 bullet casings from an assault rifle and a handgun were found at the crime scene, the Chihuahua state Attorney General's Office said.

Portillo was attacked by gunmen on Monday while driving from home to work.

More than 8,500 people have been killed in Ciudad Juarez since late 2006, turning the city into Mexico's murder capital.

At least 14,000 "armed criminals" are in Ciudad Juarez and Chihuahua city, the state capital, working for the drug cartels that are fighting for control of smuggling routes into the United States, Chihuahua Attorney General Carlos Manuel Salas said last week.

"It was an inherited war, which we got from the prior administration, in which 9,000 armed criminals are fighting for Juarez and a number near 5,000 for the city of Chihuahua," Salas said.

About 5,500 of the armed criminals operating in Ciudad Juarez belong to Los Aztecas, a gang that works as the armed wing of the Juarez cartel, while the rest work for the Sinaloa cartel, Salas said.

Some 3,000 of these criminals are minors who began to be recruited by drug traffickers in 2008 and "many of them" continue working for the cartels today, the AG said.

The violence has not subsided in Ciudad Juarez, considered Mexico's murder capital, despite the deployment of nearly 10,000 soldiers and Federal Police officers in the border city.

More than 3,100 people were murdered in Ciudad Juarez last year, making 2010 the worst year since the war between rival drug gangs sent the homicide rate skyrocketing in 2008.

The federal government claims that the murder rate in Juarez has fallen 60 percent this year, but local activists contend that it has only dropped 24 percent.

A total of 15,270 people died in drug-related violence in Mexico last year, and nearly 40,000 people have died since President Felipe Calderon declared war on the country's cartels shortly after taking office in December 2006.

Calderon has deployed tens of thousands of soldiers and Federal Police officers across the country to combat drug cartels and other criminal organizations.

The anti-drug operation, however, has failed to put a dent in the violence due, according to experts, to drug cartels' ability to buy off the police and even high-ranking officials.