DENVER -- A man once accused of killing a 3-year-old girl and then dumping her body in a ravine needs to be arrested again but he cannot be located, police said Friday.

Denver police are searching for Angel Ray Montoya, whom they once held in jail but had to release because murder charges could not be filed in time.

Denver police said Friday they have now obtained an arrest warrant for Montoya for failure to register as a sex offender but he cannot be found at his old address. Police said Montoya failed to notify the Denver police sex offender registration unit that he had changed his residence, which is required under his terms and conditions as a registered sex offender.

Anyone who has seen him or knows of his whereabouts is asked to contact the Denver Police Department's Crimes Against Persons Bureau at 720-913-6050, or Crime Stoppers at 720-913-STOP (7867).

Montoya and his girlfriend, Miriam Gallegos, were arrested after 3-year-old Neveah Gallegos disappeared. Miriam Gallegos initially told police that her daughter was snatched from her arms by two strange men, but when questioned at her home, Gallegos admitted that Neveah was dead and that she and Montoya had stuffed her body into two trash bags.

Gallegos told police that her boyfriend carried Neveah's body in a duffel bag to dump it somewhere in the Denver metro area.

After an intensive search through Denver's Dumpsters and trash bins, the toddler's body was found Sept. 24 in a ravine about 3 miles from her home. The cause of her death still hasn't been determined.

Miriam Gallegos was arrested on suspicion of false reporting, fatal child abuse and being an accessory to murder. Montoya, 22, had been arrested on suspicion of first-degree murder.

The couple was released Oct. 1 without charges because prosecutors were waiting for autopsy reports before deciding how to proceed and which charges to pursue.

District Attorney spokeswoman Lynn Kimbrough said that the decision to release the couple was the right decision based on the law, although it was not a very popular decision.

"We have the opportunity to ask for an extension, which we did," said Kimbrough. "When we became aware of the fact that we were going to need a medical examiner's final report, that includes test results and that won't be coming back for six to eight weeks, it became clear that we would not be able to hold them for that long."