A 36-year-old McHenry man is accused of taking a train to Chicago to pick up fentanyl, then riding an Uber back to Crystal Lake to deliver it to a man who died within hours. David O. Harper now faces a drug-induced homicide charge and an unlawful delivery count after prosecutors say the deal he arranged in January 2025 ended with the buyer dead in his own apartment.
According to prosecutors, the Crystal Lake man contacted Harper on Jan. 27, 2025, to buy illegal drugs, a claim detailed by Lake and McHenry County Scanner. The victim then arranged and paid for Uber rides to transport Harper to and from Metra train stations, according to WGN-TV. Harper allegedly traveled by train to Chicago, where he obtained the fentanyl, before returning to the man's Crystal Lake apartment by Uber around 9 p.m. that same night, per WGN-TV's reporting.
Investigators say Harper's phone held a photo dated Jan. 27, 2025, showing a small bag of white powder sitting on a kitchen counter, and that the counter and appliances in that image matched the kitchen where the man's body was later found, according to prosecutors. The criminal complaint lists the offense time as around 8 p.m. on Jan. 28, 2025, and alleges Harper delivered at least one gram but less than 15 grams of a substance containing fentanyl to the man, with the Crystal Lake man injecting a portion of it.
Body Found, Cause of Death Confirmed
The man was found dead inside his residence on Jan. 28, 2025, and prosecutors said his death resulted from a fentanyl overdose. A medical examiner attributed the death to the adverse effects of fentanyl, per the same account from the Scanner. The Scanner also reports that McHenry County Judge Cynthia Lamb said during proceedings that the man's body was discovered on Jan. 30, 2025 — a date that conflicts with the Jan. 28 finding reported elsewhere and attributed to prosecutors.
The Crystal Lake Police Department investigated the man's death. Prosecutors allege that after leaving the residence, Harper deleted his conversations with the man along with location records from his phone, though his phone reportedly still showed several conversations with other people about drugs and drug activity, and messages in which Harper discussed drug sale and quality with the victim over messaging apps.
Judge Orders Harper Held Without Release
A McHenry County judge issued an arrest warrant for Harper last week, and he was booked into the McHenry County jail Thursday afternoon, according to jail records cited by the Scanner. The McHenry County State's Attorney's Office then filed a petition to detain Harper pending trial, arguing his release posed a real and present threat to community safety.
Judge Lamb granted the detention petition following an initial appearance hearing Monday afternoon. In weighing the decision, she considered Harper's progress in drug court on a prior case along with his pretrial risk score of 4 out of 6, ultimately finding that no release conditions could mitigate the threat he posed. Lamb said GPS monitoring could not keep Harper from relevant risks when no specific location was identified, and that electronic monitoring would not prevent others from coming to him or him visiting others when allowed out.
A Criminal History That Includes a Prior Fentanyl Conviction
Harper was convicted on July 24, 2025, of manufacturing and delivery of fentanyl in a separate case tied to a March 25, 2025, offense, according to the Scanner's reporting. Prosecutors say he also has prior convictions for robbery, possession of a stolen vehicle, possession of a controlled substance, defrauding a drug test, and possession of drug paraphernalia.
That robbery conviction stems from a 2021 incident at the Mariano's at 105 Northwest Highway in Crystal Lake, where prosecutors say Harper shoved a 62-year-old employee who tried to stop him from stealing merchandise. Prosecutors allege he pushed a shopping cart into the employee several times and pulled a knife before fleeing the store. He was sentenced to five years in prison for that robbery.
McHenry County State's Attorney Randi Freese said her office would pursue every legal avenue to hold accountable those whose fentanyl distribution causes a death. Freese also commended the Crystal Lake Police Department for its investigation and its commitment to justice for the victim and his family. Harper is scheduled to appear in court Wednesday for a motion for substitution of judge and to set a preliminary hearing date.
Not the First Fatal Fentanyl Case Tied to Crystal Lake
This is not the only recent Crystal Lake case in which a fentanyl supplier faced homicide-related charges. A Rockford man, Markeeon L. Neal, 31, was sentenced to 10 years in prison for supplying fentanyl that led to the overdose death of a 21-year-old man in Crystal Lake, according to a separate Lake and McHenry County Scanner report. Neal pleaded guilty to an amended Class 1 felony count of unlawful delivery of a controlled substance after his more serious drug-induced homicide charge was dismissed, and McHenry County Judge Mark Gerhardt approved that plea deal, sentencing Neal to 10 years in the Illinois Department of Corrections followed by 12 months of mandatory supervised release.
Harper's charges differ from Neal's in that prosecutors have so far pursued the drug-induced homicide count alongside unlawful delivery of a controlled substance, a Class X felony and a Class 2 felony respectively. Whether that charge will hold through pretrial proceedings remains to be seen, with Harper's next court date set for Wednesday.
