Updated

Arizona's two U.S. senators said Thursday they are concerned about reports of a large number of sex-crime investigations being botched by Maricopa County Sheriff Joe Arpaio's office during a three-year period ending in 2007.

Sens. John McCain and Jon Kyl issued a written statement involving the reopening of 432 sex-crime cases — including dozens of alleged child molestations — after the sheriff's office learned the cases hadn't been investigated adequately or weren't examined at all.

"Victims of abuse not only deserve the respect of law enforcement, but their rights must also be protected throughout the criminal justice process," the statement said.

The senators said they intend to back requests from other authorities for support from the U.S. Justice Department to properly investigate the cases from Arpaio's office and other police agencies.

Arpaio responded in a written statement: "I appreciate the offer of assistance by Sens. McCain and Kyl to help this office and other major law enforcement agencies in the valley (in metro Phoenix) that currently have the same problem we did back in 2007."

Of the 432 reopened investigations, 428 have been completed, resulting in 19 arrests. The sheriff's office said 116 cases were deemed to have no basis in fact or stories that didn't add up.

Another 224 had victims who didn't want their cases pushed further, were turned down by prosecutors, or weren't submitted to prosecutors because they didn't have enough evidence.

Arpaio's office also said 69 cases had no information to pursue further

The botched sex-crimes investigations have been an embarrassment to a department whose leader calls himself "America's Toughest Sheriff" and a national hero to conservatives on the immigration issue.

Arpaio apologized for the botched cases Monday after The Associated Press outlined some of them. The situation had been reported earlier by the East Valley Tribune, The Arizona Republic, KNXV-TV and other media outlets.

In El Mirage alone, where Arpaio's office used to provide contract police services, city officials discovered at least 32 reported child molestations — with victims as young as 2 — where the sheriff's office failed to follow through, even though suspects were known in all but six cases.

Retired El Mirage police official Bill Louis, who reviewed the files, has said many of the victims were children of illegal immigrants.

Democratic U.S. Rep. Raul Grijalva and two Democratic state legislators have called for Arpaio's resignation. The concerns voiced by McCain and Kyl were the first to come from the state's GOP heavyweights.

The sheriff's office has said it has made changes to better track cases, instituted more training and moved certain employees out of the sex-crimes squad.