FORT CARSON, Colo.  For the past several years, as this Army installation in the foothills of the Rocky Mountains became a busy way station for soldiers cycling in and out of Iraq, the number of servicemen implicated in violent crimes has raised alarm.

Nine current or former members of Fort Carson’s Fourth Brigade Combat Team have killed someone or were charged with killings in the last three years after returning from Iraq. Five of the slayings took place last year alone. In addition, charges of domestic violence, rape and sexual assault have risen sharply.

Prodded by Senator Ken Salazar, Democrat of Colorado, the base commander began an investigation of the soldiers accused of homicide. An Army task force is reviewing their recruitment, medical and service records, as well as their personal histories, to determine if the military could have done something to prevent the violence. The inquiry was recently expanded to include other serious violent crimes.

Now the secretary of the Army, Pete Geren, says he is considering conducting an Army-wide review of all soldiers “involved in violent crimes since returning” from Iraq and Afghanistan, according to a letter sent to Mr. Salazar in December. Mr. Geren wrote that the Fort Carson task force had yet to find a specific factor underlying the killings, but that the inquiry was continuing.