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Classification: Murderer
Characteristics: Rape - Dismemberment
Number of victims: 1
Date of murder: March 17, 1998
Date of arrest: Same day
Date of birth: January 12, 1968
Victim profile: Karolay Adrianza, 18
Method of murder: Strangulation
Location: Miami-Dade County, Florida, USA
Status: Sentenced to death on March 24, 2003

Supreme Court of Florida


opinion SC03-800


DC#  105669
DOB: 01/12/68

Eleventh Judicial Circuit, Miami-Dade County Case # 98-8943
Sentencing Judge: The Honorable Stanford Blake
Attorney, Trial: Richard Houlihan & Kenneth White – Assistant Public Defenders
Attorney, Direct Appeal: Scott W. Sakin – Special Assistant Public Defender

Date of Offense: 03/17/98

Date of Sentence: 03/24/03

Circumstances of Offense:

On 03/17/98, two officers responded to an attempted suicide call at Michael Seibert’s apartment.  The officers knocked on the door.  Seibert eventually answered and said he was okay, told them to leave, and then shut the door. 

The officers demanded to come inside and forced their way through the door under the impression there was an emergency situation where someone could be hurt.  The officers checked Seibert for weapons and injury. 

While looking over Seibert’s apartment, one of the officers noticed a severed foot in the bath tub and yelled to the other officer there had been a homicide. Seibert took off running but was tackled and apprehended in the apartment hallway.  Seibert was then taken into custody. 

While being booked, the officer noted that Seibert’s behavior was unusual and that he acted as though he was “out of it”.  During questioning, Seibert said he was high on heroin and cocaine.

The body parts found in Seibert’s bath tub belonged to Karolay Adrianza.  Adrianza had gone out the previous evening to the beach with her boyfriend and never returned home.  Seibert had a roommate named William “Ace” Green who did not pay rent and made money by selling drugs. 

Green testified that on March 17, 1998, he saw Seibert with Karolay Adrianza and her boyfriend, Danny Navarres, in their apartment.  The three ingested a large quantity of cocaine.  Seibert sent Green and Navarres to the store to buy cigarettes and beer.  When they returned, Navarres did not enter the apartment and said he had to go buy something and would be back later. 

When Green arrived back at the apartment alone, Adrianza asked for her boyfriend and made several phone calls to see where he was.  After about 30 minutes, Seibert asked Green to leave and keep an eye out for Navarres stating that he wanted to be alone with Adrianza. 

Green had noticed that Seibert had been flirting with Adrianza.  Green left the apartment and went to a laundromat to talk to a friend who worked there.  After a while, Green wanted back into the apartment.  He did not have a key so he called several times, but Seibert would not answer. 

Green then knocked on the door and Seibert said to come back later making comments that he only needed a little bit longer before he would be in her pants.  Later on, when Green knocked on the door again, Seibert asked him to go buy some cigarettes.  Green refused and said he wanted inside.  An argument occurred and, at one point, Seibert stated he was going to kill himself.  Green then called the police and reported a suicide attempt.

Adrianza’s body was in the bath tub clothed in a shirt and underwear.  Most of the soft tissue below her waist had been removed (approximately 40 to 50 pounds) which included part of her abdominal wall, the large bowel and part of the small bowel, which had been flushed down the toilet.  Adrianza’s left hand, left foot and left ankle and been separated from the body.  Examiners estimated that the cutting and flushing of her body that Seibert did would have taken about an hour. 

Adrianza died from strangulation. There was also evidence of Seibert’s semen inside Adrianza’s body.  It could not be determined if Seibert had sex with Adrianza before or after her death.

Prior Incarceration History in the State of Florida:




Prison Sentence


Kidnap; Comm. or Fac. Felony


15Y 0M 0D


Grand Theft Motor Vehicle


5Y 0M 0D


Burg Unoccstruc/CV or Att.


15Y 0M 0D


1st DG Mrd/Premed. Or Attempted


30Y 0M 0D


Kinap; Comm. or Fac. Felony


30Y 0M 0D


Grand Theft Motor


5Y 0M 0D

Trial Summary:

04/01/98          Indicted as follows:

Count I:           First-Degree Murder

11/21/02          Jury returned guilty verdicts on the sole count of the indictment.

02/11/03          Jury recommended death by a vote of 9-3.

03/24/03          Sentenced as follows:

Count I:           First-Degree Murder – Death

Case Information:

On 04/28/03, Siebert filed a direct appeal to the Florida Supreme Court.  Seibert claimed that error occurred in the court denying his motions to suppress evidence and statements from the police entering his apartment non-consensually without a warrant, thus violating Siebert’s constitutional rights.  He also contended that error occurred in the trial court refusing his motion for mistrial based on irrelevant and highly prejudicial evidence presented by the state, which violated his Fourteenth Amendment right.  In his appeal, Siebert also argued that, under the circumstances of his case, the death sentence is disproportionate and violates the Constitution.  Siebert argued that the jury did not have a fair consideration in the sentencing recommendation due to the prosecutor’s improper and prejudicial reference to irrelevant criminal activity as a non-statutory aggravating circumstance. His final arguments referred to the Florida Capital sentencing scheme as being unconstitutional for several reasons. 

The Florida Supreme Court affirmed Seibert’s conviction and sentence on 02/16/06.

On 06/28/06, Seibert filed a Petition for Writ of Certiorari in the United States Supreme Court that was denied on 10/02/06.

On 09/11/07, Seibert filed a 3.850 Motion for Post-Conviction Relief in the State Circuit Court.  This motion is currently pending.


Freed kidnapper facing execution after resorting to murder

Monday 25th Nov 2002

A MAN freed from jail after serving only one-third of his sentence for the attempted murder of a Hampshire tourist is facing the death penalty in the USA after butchering a young woman.

Michael Seibert used a shoelace to choke an 18-year-old American student before placing her body in the bath, cutting off a hand and foot and flushing chunks of her flesh down the lavatory.

The 1998 crime came less than a year after Seibert won an early release from a Florida jail, having served only ten years of a 30-year sentence for bludgeoning Kathryn Jones from Southampton.

Ms Jones, then 27, was left for dead in a field after being abducted from a telephone box in Miami Beach while on holiday in 1986.

Seibert took her to a secluded field and smashed her head with a porcelain toilet until she passed out, leaving her with severe brain injuries.

When found, she was close to death and spent three weeks in a coma before being flown home to Eastleigh for further extensive treatment at Southampton General Hospital, where she had previously worked as a nurse.

She first regained consciousness when her boyfriend Roger Jones was flown over to Miami. Medical staff advised him to shout in her ear and after several hours of bellowing he got through to her.

Initially she could remember nothing of her holiday or of the attack and could say little apart from her own name.

Ms Jones, formerly of Winchester Road, took advantage of a last-minute standby ticket to fly to Florida for a two-week holiday. Seibert attacked her as she was about to take a day-trip to Key West, the southern-most tip of the United States.

Court records revealed that when arrested for Karolay Adrianza's killing four years ago, Seibert told police: "My parents are really going to be upset at me. This is the second time I've been in trouble."

Seibert, 34, is charged with first-degree murder for the killing of Adrianza, who had attended a party at his Miami Beach apartment on March 16, 1998.

According to court documents, Seibert's flatmate William "Ace" Greene called police at 10am the following morning to say he had been shut out of the apartment and feared Seibert may be about to commit suicide inside. He claimed to have heard Seibert shout: "I'm losing it, I'm going to kill myself."

Police later forced their way into the property and detained him after finding Ms Adrianza's butchered body in the bath.

Seibert, a former restauarant dishwasher, had been using cocaine and heroin that night, court documents revealed.

Greene's testimony was videotaped earlier this year through a satellite link-up between a Miami courtroom and a prison in Ecuador, where he is serving time for drugs offences.

Prosecutor Flora Seff wants Seibert sent to the death chamber when he is sentenced next year.

Seibert has always publicly denied the attempted murder of Kathryn Jones, but was linked by forensic evidence and later bragged about the incident to fellow inmates while being held in custody.

People in Florida were so horrified by her ordeal that they set up a fund for her which, along with contributions from colleagues and former patients in Southampton, raised more than £16,500.

Since Seibert's early release in 1997, US law has been changed to ensure that violent criminals serve at least 85 per cent of their sentences.


Michael Seibert



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