Arizmendi was last seen in Wethersfield, Connecticut on July 25, 2003. She was accompanied by William Devin Howell at the the time; they were riding in his 1985 Ford Econoline van. Photographs of Howell and the van are are posted below this case summary. Arizmendi and her boyfriend had been smoking crack cocaine with Howell in their motel room, and then Howell and Arizmendi left to go get more drugs. Arizmendi has never been heard from again. Her sister reported has a missing person on July 31.

Howell was later arrested in North Carolina for crimes unconnected to Arizmendi's disappearance. Connecticut police obtained a warrant and searched his van on April 22, 2004. Arizmendi's blood was found on a seat inside the vehicle; it had soaked through the fabric and into the foam beneath. The seating portion of the van's back bench had been removed and replaced with three sofa cushions. A substantial amount of blood from another female person, as yet unidentified, was also present.

On May 13, 2005, Howell was arrested in Virginia and charged with Arizmendi's murder. At the time of her disappearance, he was living in Connecticut and earned his living doing odd jobs and cutting grass at homes and businesses in Wethersfield, Hartford, New Britain and West Hartford. Howell told authorities Arizmendi's blood was in his van because she and her boyfriend had gotten into a fight there. He was on trial in January 2007 when he pleaded guilty to manslaughter. He was sentenced to fifteen years in prison. Howell entered an Alford Plea, meaning that he did not admit he had killed Arizmendi but acknowledged there was sufficient evidence to convict him in her death. He also pleaded guilty to intimidating a witness.

Arizmendi's remains have never been located. Authorities believe Howell may have also murdered the unidentified female whose blood was found in his van, but he has not been charged.

Left: William Devin Howell;
Right: Howell's van