Marian Bagni said Seattle police informed her of the identification earlier in the day, and the The King County medical examiner's office says the death was a homicide.
The cause of death has been listed as "multiple sharp force injuries."
Police said the owner of the house in the 2000 block of 3rd Avenue West found the body on Thursday afternoon. Mike Webb had been living in the rental home until he disappeared in April.
Webb was last seen on April 13th and had been reported missing.
The property owner, David Neth, said he found the body while clearing out a crawl space in the home. He said the body was underneath a blue tarp, and he immediately called police.
"There were 2 other unusual items in the crawl space where the body was found that seemed very strange to me but I do not want to talk about them at this point," Neth said in an e-mail.
The suspicion of Webb's family and friends are turning to the four or five people who continued to live at the house after Webb disappeared. Bagni said investigators do know the identities of those people.
Neighbor Derek Evans said he worried about a number of bad choices Webb was making including the people he was hanging around with. He said he became progressively concerned particularly after noticing a syringe on Webb's garage roof.
"Looked really sketchy, starting to make us and the other neighbors pretty nervous," he said. "They were people that just didn't fit into the neighborhood at all."
A makeshift memorial has begun to take shape in front of Webb's house. Bagni said Webb's family is taking one day at a time and focusing on the investigation. She said Webb's friends have been a source of strength.
"People are calling and writing, Mike was a pretty solitary guy, so I didn't know he had so many wonderful friends," she said.
Webb, 52, hosted a liberal talk show on KIRO-AM/710 radio for ten years. He was fired in December of 2005 when he was being investigated for insurance fraud.
The charges against Webb stemmed from a 2005 car wreck that caused about $6,000 in damage to Webb's Lexus when an uninsured driver hit it. King County prosecutors argued successfully that Webb bought a comprehensive insurance plan the day after the crash and filed a claim for the damage.
Webb's trial was thrown out after jurors saw Webb in the midst of a nervous breakdown outside the Seattle courthouse. He later spent 30 days at an inpatient mental health facility.
In a truncated second trial, Superior Court Judge Julie Spector found Webb guilty of felony insurance fraud and sentenced him to 240 hours of community service. Spector also ordered Webb to continue mental health treatment for an unspecified condition.
Webb was convicted of fraud charges earlier this year, but has denied any wrongdoing and has claimed the evidence against him were fabricated as part of a conspiracy.
The missing-person report also notes that Webb was in a doctor's care.
In an interview with the Seattle P-I after his conviction, Webb denied any wrongdoing and claimed that the evidence against him had been fabricated as part of a conspiracy.
According to the missing-person report, Webb's family was concerned for his safety because he had recently been spending time with a "shady character" that had previously taken a car from Webb. Police declined to release the individual's name.
Longtime friend John McMullen said Webb was last seen April 13, but his family continued to receive text messages from Webb's cellphone for another month.
Although the messages indicated he was fine, and leaving town, Webb did not normally use text messages and his family eventually demanded that Webb call them, McMullen said. The messages stopped, and Webb's sister filled a missing person's report May 14.
Webb said in February that the felony conviction and his firing from KIRO turned his life "upside down." All that kept him going, he said, was making nightly broadcasts online at mikewebb.org.
"The one thing that's been a salvation for me is that show that I've done every night," Webb said in February.
Webb's voice has been missing from the Web site since mid-April. A notice has been posted on the site to tell fans Webb is missing.