Another law enforcement search for the body of Stacy Peterson, a Chicago-area mother of two who remains missing since her disappearance 14 years ago, turned up empty Tuesday after the woman’s sister said she submitted a tip back in May about supposed skeletal remains located in a canal.

Stacy Peterson disappeared on Oct. 28, 2007, from her home in the Chicago suburb of Bolingbrook, where her husband, Drew Peterson, previously served as a police sergeant. Her sister, Cassandra Cales, has long believed that Drew killed Stacy, who was his fourth wife, and disposed of her body. 

Diving teams entered the water Tuesday five months after Cales said she submitted a tip in May that her privately employed sonar search crews captured video of supposed skeletal remains in the Des Plaines River near the Lockport Powerhouse, which is a power station north of Joliet, Illinois. 

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"I'm not going to stop. If you want it done right, you have to do it yourself," Cales told Fox 32 Chicago. 

"I am beyond frustrated. It's definitely somebody," Cales said of what appeared to be bones captured on video in an area of murky water about 21 feet deep. "I can't say it's my sister. But why take so long to go and retrieve something?" 

For over the past decade, Cales said she has organized searches, most recently with the help of a man from Alaska who specializes in underwater searches with a remote-operated vehicle, WGN reported. 

Searches conducted by the FBI and Illinois State Police Tuesday turned up empty once again. 

A photo of former Bolingbrook police officer Drew Peterson, and his wife, Stacy, adorned the dresser in their bedroom at their family home on March, 20, 2008 in Bolingbrook, Ill. (AP Photo/M. Spencer Green)

A photo of former Bolingbrook police officer Drew Peterson, and his wife, Stacy, adorned the dresser in their bedroom at their family home on March, 20, 2008 in Bolingbrook, Ill. (AP Photo/M. Spencer Green) (AP Photo/M. Spencer Green)

"The Illinois State Police with the assistance of the Federal Bureau of Investigation searched an area of the I&M canal near Lockport," the Illinois State Police said in a statement Tuesday, according to Fox 32.  "This area has been searched before in recent months with unsuccessful results. The search today was also unsuccessful. No further information is available at this time."

At a press conference Tuesday, Cales said, "I've basically devoted my life to searching." She told reporters that she is dedicated to finding her sister’s remains to give her a proper burial and prove to her children that their mother never abandoned them, WLS reported. 

"How many times do I have to hand my sister or whoever it is to them on a silver platter, and again they do nothing?" she said. "We told him about this in May. But they waited five months to search."

The Illinois State Police Division of Criminal Investigation Zone 3, with assistance from the FBI, was working "an active and ongoing criminal investigation" earlier Tuesday, but no further information would be released at that time in order to "protect the integrity of the case," WGN reported.

Drew Peterson, who has never been formally charged in Stacy’s disappearance, is serving a 38-year sentence in the 2004 death of his third wife Kathleen Savio. He'll follow that with 40 additional years after a conviction in 2016 on allegations that he plotted to kill the prosecutor who put him behind bars. 

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Savio’s body was found in a bathtub and initially ruled an accident. But Will County State’s Attorney James Glasgow ordered the case re-opened following Stacy Peterson's disappearance in 2007. Though he maintains his innocence, Drew Peterson was convicted of Savio’s murder in 2012, and the Illinois Supreme Court upheld that conviction in 2017. 

Peterson was recorded telling fellow Illinois state prison inmate Antonio Smith he was worried that Glasgow would eventually charge him in Stacy’s disappearance. Peterson was later moved to a federal lock-up in Terre Haute, Indiana. Eligible for parole in 2081, he is still appealing his murder-for-hire conviction in state courts. Stacy was 19 and Drew was 49 when they initially got married. 

Fox News’ Travis Fedschun and The Associated Press contributed to this report.