A Janesville man is accused of killing another man by supplying the heroin cocktail that killed him Nov. 29.

Taiwan R. Edwards, 23, of 607 Lyndhurst Drive, was charged in Rock County Court on Friday with first-degree reckless homicide.

The charge carries a maximum of 40 years in the prison system.

Matthew J. Splinter, 44, died Nov. 29 from a mixture of heroin, two variants of the synthetic opioid fentanyl and gabapentin, a prescription drug used to treat seizures and nerve pain, according to the criminal complaint.

The pathologist who performed the autopsy described the process leading to death: slowed breathing, loss of consciousness, brain injury due to lack of oxygen and coma, according to the complaint.

A person who knows Splinter told detectives he had suffered from addiction for a long time and had been clean for three or four weeks. He began using again after taking up with a female companion, according to the complaint.

Splinter and the woman visited their heroin dealer in Janesville on Nov. 28 and waited about 30 minutes for the dealer’s supplier to bring the drugs, according to the complaint.

The supplier was Edwards, the complaint alleges.

A detective found phone records showing Edwards had communicated with the dealer by voice or text 10 times the evening of Nov. 28, according to the complaint.

Splinter and the woman used a small amount of the drugs at the dealer’s residence. They then went to the woman’s residence, and Splinter left her residence that night, she told detectives.

Splinter was pronounced dead at 8:54 a.m. the next day at his residence. He was found lying on the floor of a bathroom. A syringe with liquid in it was found in the sink. Nearby were a baggie corner that likely contained the drugs and two syringe caps, according to the complaint.

Inside Splinter’s wallet was another baggie corner with an off-white powder in it, wrapped in a $20 bill.

Edwards was held on a $1,000 cash bond after his initial court appearance Friday. His next court appearance is Wednesday.