Nobert Matara admitted waiting inside Tracy Nyariki’s home before killing her and transporting her remains across state lines.

WILMINGTON, Del. — A Delaware man has been sentenced to life in prison for killing his former girlfriend inside her New Castle County apartment, placing her remains in a suitcase and driving to a Maryland hotel before authorities found him three days later.

Nobert Matara, 33, received the life sentence June 26 in New Castle County Superior Court after pleading guilty to first-degree murder in the death of Tracy Nyariki. The Delaware Department of Justice announced the sentence July 2. Matara had entered his guilty plea April 29, resolving the criminal case without a trial. State prosecutors said a life term was mandatory under the plea and conviction. The sentence brought the court proceedings to a close more than 18 months after Nyariki disappeared from her home shortly before Christmas 2024.

The case began with an attack on Dec. 17, 2024, according to the account released by prosecutors after Matara’s plea and sentencing. Authorities said Matara went into Nyariki’s apartment and remained there for several hours while waiting for her to return. After she came home, he attacked and killed her. Prosecutors said Nyariki suffered 58 stab wounds. They said Matara then dismembered her body, put the remains into a suitcase and removed the suitcase from the apartment. Officials have not publicly described how Matara entered the residence or what happened between the former couple before the attack.

Matara later drove from Delaware to Aberdeen, Maryland, with the suitcase in the trunk of his vehicle, prosecutors said. Aberdeen is northeast of Baltimore and across the state line from New Castle County. Police eventually located Matara at a hotel there. The Delaware attorney general’s office said Nyariki’s body was still in the trunk when authorities found him. The interstate movement added another location to an investigation that had started at her apartment and required coordination among officers in Delaware and Maryland.

Police did not initially know that Nyariki had been killed. New Castle County officers were sent to the 2700 block of Stone Place in the Village of Kent Apartments at about 10:12 p.m. Dec. 20 after her employer reported that she had missed work for several days. Officers entered or searched the apartment as part of the welfare investigation but did not find her there. Police said they observed suspicious circumstances that caused them to fear for her safety and led detectives to treat the disappearance as a possible crime rather than an unexplained absence.

That report from Nyariki’s workplace created the first documented opening for police intervention. Investigators began tracing where she had been, whom she had been with and what had happened inside the apartment. Their work soon led them to Maryland and Matara. Human remains found in his vehicle were identified as Nyariki’s, and he was taken into custody. Authorities have not released a complete public timeline showing every investigative step between the late-night welfare check in Delaware and the discovery at the Aberdeen hotel.

At the time of the initial investigation, police described Nyariki as 31. Later releases from the Delaware Department of Justice identified her as 33. The reason for that difference has not been explained publicly. The state’s central account, however, has remained consistent on the main sequence: Nyariki was killed in her apartment Dec. 17, her employer contacted police after she stopped reporting to work, and Matara was found in Maryland with her remains on Dec. 20.

Matara’s April guilty plea changed the legal posture of the case. By admitting first-degree murder, he gave up the right to require prosecutors to prove the charge to a jury beyond a reasonable doubt. The plea also avoided a public trial in which witnesses, investigators and forensic specialists might have been called to describe the evidence. Delaware officials said at the time that Matara faced a mandatory life sentence, leaving the later sentencing hearing to formally impose the punishment required for the offense.

Attorney General Kathy Jennings described the crime as exceptionally disturbing when the plea was announced. She thanked the New Castle County Police Department and the state trial team for their work and said they had pursued justice for Nyariki and her family. After the life sentence was imposed, Jennings again credited the investigators and prosecutors. She also said her thoughts were with Nyariki’s relatives and expressed hope that the outcome would offer them some measure of peace and closure.

The attorney general’s comments focused on the completed prosecution, but the sentence cannot restore what Nyariki’s family, friends, patients and co-workers lost. An obituary described her as having grown up in Nairobi, Kenya, before moving to the United States. It said she came to the country to pursue her goal of becoming a nurse and was remembered for the care and generosity she showed other people. Those details presented a life centered on work, family and service, in contrast with the limited public identity created by the criminal case.

Accounts published after Nyariki’s death said she had lived in the United States for about five years. Her obituary said she left a lasting impression on patients, colleagues and others who worked with her. A fundraising appeal organized after her death described her as a daughter, sister and friend whose warmth affected the people around her. While those statements came from memorial materials rather than court testimony, they provide the clearest public account of who Nyariki was beyond the official language used in police and prosecution releases.

The investigation also shows the role that routine workplace concern can play when a person unexpectedly vanishes. Nyariki’s employer did not treat her repeated absences as ordinary and contacted authorities. That call brought officers to Stone Place, where the circumstances inside the home prompted a wider investigation. Police have not publicly said whether relatives or friends had also tried to reach her before the welfare check, nor have officials released a detailed description of the evidence found in the apartment.

Authorities have also not announced a motive in the public statements reviewed for this report. Matara and Nyariki were described as former romantic partners, but prosecutors did not say why he went to her home, why he waited there or what led to the killing. No public account has established whether Nyariki knew he was inside the apartment before she returned. The absence of a released motive does not change the conviction, which rests on Matara’s guilty plea, but it leaves one of the case’s most personal questions unanswered.

Officials have used restrained language in their formal announcements while still disclosing the severity of the crime. The number of wounds and concealment of Nyariki’s remains were included because they formed part of the prosecution’s account and helped explain the first-degree murder case. Other details of her injuries have not been broadly released, and they are not necessary to understand the conviction or sentence. The central legal development is that Matara admitted intentionally killing Nyariki and is now serving a life term.

The life sentence ends the main criminal proceeding in New Castle County Superior Court. No trial or additional sentencing date is pending in the first-degree murder case, and state officials have not announced any remaining charges tied to the movement of Nyariki’s remains. Matara remains in state custody under the judgment imposed June 26. For Nyariki’s family and community, the court’s work is finished, but the consequences of her death continue beyond the case file.

Author note: Last updated July 31, 2026.