PORTLAND — The father of Ayla Reynolds, the toddler who disappeared from her Waterville home in December 2011, is facing a charge of domestic violence assault for an alleged attack on a former girlfriend.

Justin DiPietro, 26, was arrested in Portland a week ago. The alleged victim in the case is one of three people who were at the house with Reynolds the night she disappeared. Police have said they do not believe Reynolds, who was 20 months old at the time, is still alive.

Portland police say a lieutenant spotted Justin DiPietro, 26, in front of 88 Spring St. at 11:15 p.m. July 6. He and Courtney Roberts, 25, were arguing when he grabbed and pushed her, a police statement said.

DiPietro was charged with domestic violence assault and is free on bail.

Court records show DiPietro was ordered after his arrest to have no contact with Roberts as a condition of bail.

No one answered the door Monday at the home of DiPietro’s mother, Phoebe DiPietro, at 29 Violette Ave. in Waterville — where Ayla Reynolds was last seen.

Neighbors said Phoebe DiPietro works outside the home and Justin DiPietro no longer lives there, though court papers show that he still lists that as an address.

A sign next to a maple tree on the lawn bears Ayla’s photograph and the words “Missing, Ayla Bell Reynolds, Please call 911.” A “No Trespassing” sign hangs on the tree.

DiPietro has been at the center of one of the biggest investigations in Maine State Police history, first while police tried to find the girl, then as they tried to find out what happened to her after saying they believed she was no longer alive.

DiPietro called police the morning of Dec. 17, 2011, to report that the girl had disappeared from her room the night before.

Nobody has been charged but police have said they do not believe that DiPietro or two other adults home at the time — his sister Elisha DiPietro and Roberts — have told all they know about her disappearance.

Reynolds’ mother, Trista Reynolds, was not at the house.

Ayla Reynolds’ grandfather, Ronald Reynolds, 53, of Mona Road in Portland, was charged this spring with threatening a family member with a knife, police said. When officers arrived at the home at 6 p.m. on May 31, Reynolds resisted and police used a Taser on him, police said.

Police said that incident had nothing to do with Reynolds’ granddaughter.

David Hench can be contacted at 791-6327 or at:

dhench@pressherald.com