SEATTLE -- A lawyer for the family of missing West Valley City mom Susan Cox Powell announced that federal authorities are now investigating her disappearance.
Anne Bremner said Tuesday that federal authorities are continuing the investigation that West Valley City police have said has gone cold.
"This is not over, and there will be further investigation in this case involving Susan Cox Powell's disappearance and all the other circumstances that we know about," Bremner said.
Bremner said she could not name the federal agency investigating the disappearance, but said they were looking at Susan's father-in-law, Steven Powell.
"I can say that it partially involves Steven Powell in terms of what he knew and what he can say and what he can tell us about what happened to Susan," she said.
Steven Powell is currently serving a prison term in Washington state after being convicted of voyeurism. When they announced the end of the active investigation, West Valley City Police Deputy Chief Mike Powell (no relation to the Powell family in question) said it was likely that he did not have anything to do with Susan's disappearance.
But in the 30,000 pages of documents that West Valley City police released to FOX 13 on Monday, detectives suspected Steven Powell of involvement in Susan's disappearance. They noted that he took two days off right after Susan vanished, but claimed he never came to Utah and his son never traveled to Washington.
"It is suspected that Steven Powell and Joshua Powell could have possibly met during this time," an officer wrote in one report. "It is also suspected that Steven Powell may have more knowledge about the disappearance of Susan Powell than what he is sharing with the detectives."
Josh Powell was considered a "person of interest" throughout the investigation. Police reports indicate detectives were pursuing Josh as having something to do with his wife's disappearance and looking at others that may have helped him dispose of her body. Most recently, police focused on Josh Powell's brother, Michael Powell.
The documents were being reviewed by Bremner and Susan's father, Chuck Cox. He told reporters on Tuesday that there were several revelations in the police files that shocked him -- among them, the claim that Josh Powell had an affair with a woman months before Susan vanished.
"Michael's involvement and everything and his car, that was a big shock to me," Cox said.
He said the massive trove of documents will help the family plan future searches for Susan. The family has already hired a private investigator to help them.
West Valley City police have said their case against Josh Powell was largely circumstantial. Cox said he believed there was enough for a prosecutor to level charges.
In a statement to FOX 13 on Tuesday night, the U.S. Attorney's Office for Utah said it was not conducting any investigation.
"The U.S. Attorney's Office and federal law enforcement agencies in Utah have provided assistance to the West Valley City Police Department, at the police department's request, at various times during the course of the investigation," spokeswoman Melodie Rydalch said.
"If there are new developments in the case in the future, and the West Valley City Police Department requests our assistance, we would be willing to assist again. At this time, however, we do not have any plans to conduct any further investigation."