Mexico City ? Chihuahua state authorities vowed Friday to find those responsible for killing a prominent lawyer who was a vocal critic of the investigation into the slayings of women in and around the border city of Ciudad Juarez.

Juarez lawyer Sergio Dante Almaraz was shot several times inside his SUV on Wednesday as he waited for a traffic light to change in the city’s downtown. A companion was injured and remains hospitalized.

Almaraz, who was buried Friday, was best known for his tireless work in defending bus drivers Victor Garcia Uribe and Gustavo Gonzalez Meza, who were jailed in the killing of eight women. The women’s bodies were found in November 2001, dumped in a cotton field in Juarez.

Last year, after years of court wrangling, Garcia was released from jail. Gonzalez died during an operation in jail.

At a news conference Friday in Chihuahua City, Gov. Jose Reyes Baeza pledged to “launch the most effective, efficient operation to find the culprits of this hideous crime.”