"I really don't know what to think of it," Clark tells ET exclusively. "I can't believe someone gave a police officer what appears to be, could be, important evidence in a case -- even if it is closed -- and takes it home. I don't know what to say about that except I can't believe it, but it's apparently what happened."
Of course, she still remains skeptical.
"I don't know whether to say it is truly evidence, none of us knows that yet -- it might be a hoax, it might be somebody who planted it and then just pretended to find it and gave it to the off-duty police officer, you don't know," Clark says. "But, of course, I'm glad the LAPD is taking it seriously and subjecting it to testing so we can find out."
Clark notes that DNA evidence could still be potentially recovered from the knife, if it is indeed not a hoax.
"It's very possible -- I mean, they recover DNA on mummies in Egypt," Clark says. "It's entirely possible that if there is some DNA to be recovered, that it could be found, especially with today's technology, which is much more sensitive."
"I think it's a remarkable development if it does turn out to be connected to the murders of Ron and Nicole," she adds. "It would be interesting if there was some evidence on that knife that pointed to who might have helped to bury it, if indeed someone else did."
Photos from the case:
Key Players in the OJ Simpson Trial
EXCLUSIVE: Marcia Clark on knife allegedly found at O.J. Simpson's estate: 'I'm glad the LAPD is taking it seriously'
FILE - In this Wednesday, June 21, 1995 file photo, O.J. Simpson holds up his hands before the jury after putting on a new pair of gloves similar to the infamous bloody gloves during his double-murder trial in Los Angeles. The return of O.J. Simpson to a Las Vegas courtroom next Monday, May, 13, will remind Americans of a tragedy that became a national obsession and in the process changed the country's attitude toward the justice system, the media and celebrity. (AP Photo/Vince Bucci, Pool, File)
Defense attorney Robert Shapiro (L) sits next to O.J. Simpson during a preliminary hearing following the murders of Simpson's ex-wife Nicole Brown Simpson and her friend Ronald Goldman July 7, 1994 in Los Angeles. (Photo by Lee Celano/WireImage)
Johnnie Cochran Jr., left, and Gerald Uelmen leave the Criminal Courts Building following the arraignment of O.J. Simpson on murder charges Friday, July 22, 1994, in Los Angeles. Cochran, who is a high-profile attorney known for his trials kills and links to the city's African-American community, is the latest addition to Simpson's defense team, which also includes Uelmen. (AP Photo/Chris Martinez)
LOS ANGELES, CA - FEBRUARY 27: Prosecutor Marcia Clark complains to the judge 27 February about a second statement by Rosa Lopez, a key defense witness, that was not released by the defense. Lopez, a housekeeper to a neighbor of O.J. Simpson's, claims to have seen a white Ford Bronco outside his home at around the time the prosecution claim the murders of Nicole Brown Simpson and Ron Goldman took place. AFP PHOTO (Photo credit should read POO/AFP/Getty Images)
Witness Brian "Kato" Kaelin testifies under direct examination during the O.J. Simpson double-murder trial at the Los Angeles Criminal Courts Building in this Tuesday, March 21, 1995 photo. (AP Photo/John McCoy, Pool)
FILE - This file photo combo shows O.J. Simpson's ex-wife Nicole Brown Simpson, left, and her friend Ron Goldman, both of whom were murdered and found dead in Los Angeles on June 12, 1994. O.J. Simpson was arrested in connection to the murder and acquitted of the crime. Simpson is now serving nine to 33 years in a Nevada prison after a jury found him guilty in 2008 of leading the gunpoint robbery of two sports memorabilia dealers in Las Vegas, and he's seeking a new trial because he says his longtime lawyer failed to disclose that he knew about the plan in advance and told Simpson it was legal and provided bad advice at trial. (AP Photo/File)
FILE--Los Angeles Police Detective Mark Fuhrman testifies in the Simpson double-murder trial in Los Angeles Thursday, March 9, 1995. The calm, controlled voice of Mark Fuhrman sliced through the O.J. Simpson courtroom Tuesday on racially explosive tapes offered by the defense to unmask the detective as ``L.A.'s worst nightmare,'' a racist, lying policeman. It was the same voice jurors heard months ago when the investigator who found the bloody glove on Simpson's property swore under oath that he had not used the word ``nigger'' in the last 10 years. (AP Photo/Pool, Kim Kulish)
Los Angeles Police Department Det. Philip Vannatter denied lying to the jury in the O.J. Simpson trial when he testified that he didn't consider Simpson a suspect when investigators entered his estate without a warrant Tuesday, Sept. 19, 1995, at Simpson's double-murrder trial in Los Angeles. (AP Photo/John McCoy, Pool)
Los Angeles Police Department criminalist Dennis Fung, right, arrives with Brown family attorney, John Kelly, at the Los Angeles County Superior Court in Santa Monica, Calif. on Tuesday, Nov. 5, 1996 for the wrongful-death civil case against O.J. Simpson. Fung was on the stand on Tuesday. (AP Photo/Michael Caulfield)
Potential O.J. Simpson alibi witness Rosa Lopez testifies in Los Angeles Superior Court Thursday, March 2, 1995, without the jury present during Simpson's double-murder trial. The woman billed in Johnnie Cochran Jr.'s opening statement as the Maid With the Alibi came to court in late February, testified under protest, hopped on a plane to El Salvador and hasn't been heard from since. (AP Photo/Blake Sell, Pool)
Limousine driver Allan Park, left, testifies while attorney Johnnie Cochran Jr. displays a bag during the O.J. Simpson double-murder trial in Los Angeles Wednesday, March 29, 1995. (AP Photo/Hal Garb, Pool)
Prosecutor Christopher Darden points at a chart during his closing arguments as Marcia Clark looks on, Friday, Sept. 29, 1995, in a Los Angeles courtroom during the O.J. Simpson double-murder trial. Darden said to the jurors ``It's time to stand up. It is time to stand up. The Constitution says a man has no right to kill and get away with it just because one of the investigating officers is a racist.'' (AP Photo/Reed Saxon, pool)
LOS ANGELES, CA - JUNE 19: O.J. Simpson (R) whispers to Defense attorney F. Lee Bailey (L) during testimony of FBI special agent William Bodziak 19 June during the O.J. Simpson murder trial in Los Angeles. Bodziak compared one of O.J. Simpson's tennis shoes to a model of the Italian-made Bruno Magli shoes, which left imprints at the murder scene of Nicole Brown Simpson and Ronald Goldman. AFP PHOTO (Photo credit should read POO/AFP/Getty Images)
LOS ANGELES, CA - JUNE 16: O.J. Simpson defense attorney Alan Dershowitz (standing) gestures during a motion to Judge Lance Ito 16 June in which he said that the standard of juror dismissals must be changed. The defense has accused the prosecution of juror targeting and hiding witnesses. Seated are (L-R) prosecutor Marcia Clark and Scott Gordon. AFP PHOTO (Photo credit should read POO/AFP/Getty Images)
Defense attorney Barry Scheck, right, continues his cross- examination of Los Angeles Police criminalist Collin Yamauchi, Friday, May 26, 1995, during the O.J. Simpson double-murder trial in Los Angeles. (AP Photo/Kevork Djansezian, Pool)
Los Angeles Superior Court Judge Lance Ito yells in court during the O.J. Simpson double-murder trial in Los Angeles Friday, Sept. 29, 1995. (AP Photo/Eric Draper, Pool)
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Though Clark points out that the chances of this leading to any sort of prosecution is unlikely.
"The likelihood of any prosecution stemming from this evidence is very, very slim," she admits. "But we have to find out what this means -- what the truth of this is."
"I just hope the truth comes out about this situation, as I always do about all situations -- whatever this is, let's find out," she adds. "Let's find out if it's related or not. I really want to say -- my heart goes out to the families. With these kind of things that stir up all these memories and the pain of it all, I just can't imagine how they're feeling right now."
In a press conference on Friday morning, LAPD Capt. Andrew Neiman confirmed that the department is investigating the alleged discovery of a knife on the Rockingham property formerly owned by Simpson. He declined to name the retired officer involved in the discovery of the knife, although according to the Los Angeles Times, a construction worker found the knife years ago and turned it over to the police officer in question.
According to TMZ, the officer informed Robbery Homicide detectives of the knife's existence because he wanted to get it framed.
Clark, 62, was the head prosecutor during Simpson's trial, and ended up taking a leave of absence from her job after the former NFL star was acquitted of the murders of his ex-wife, Nicole Brown Simpson, and her friend Ron Goldman in 1995. Clark retired two years later, but went on to co-author a book about the case titled Without a Doubt.
Simpson, 68, remains in a Nevada state prison after he was arrested in connection with a robbery at a Las Vegas hotel room in September 2007. He was found guilty on 12 counts, including kidnapping and armed robbery, in October 2008, and was later sentenced to 33 years in jail. Simpson is still eligible for parole in November of 2017 -- at the age of 70 -- his lawyer, Ozzie Fumo, tells ET, unless he receives a sentence reduction through other means.
On Friday, Neiman said that it is his understanding that could Simpson could not be retried on murder charges, as he was previously acquitted.
"I think the series actually makes an effort to acknowledge them and the ways in which that they were forgotten," Clark said. "This is an important series that's beautifully done, very compelling and I can't thank Ryan Murphy enough for what he's done here in terms of raising these issues in a very serious and compelling and very substantive way."
"But at the end of the day, two people lost their lives in a brutal murder," she added. "So we have to remember that. We can't forget them again. Remember Ron and Nicole."