Steven Mark Chaney

The Crime

Shortly before midnight on June 20, 1987, 27-year-old John Sweek and his 21-year-old wife, Sally, were found murdered in the kitchen of their apartment in Dallas, Texas. They had been stabbed.

Police found dozens of fingerprints as well as what appeared to be a human bite mark on Mr. Sweek’s left arm. A trail of shoe prints left in dried blood began on the linoleum in the kitchen, went into the carpeted dining room, and continued through the living room to the front door.

The Investigation

Dallas Police Crime Scene Investigator James Vineyard believed some prints were made by a flat-heeled shoe, while others had a gap between the sole and the heel. One of the bloody shoe prints in the kitchen appeared to show a pattern of parallel lines left by a design on the sole of the shoe. There was so much blood spattered throughout the kitchen that Investigator Vineyard concluded the attacker or attackers would have had significant amounts of blood on their shoes and clothing.

Sweek family members told Dallas Homicide Detective John Westphalen that John and Sally sold drugs and that a man named Juan Gonzalez was their supplier. About a week after the murders, one of Sally’s sisters gave Detective Westphalen a spiral notebook she found in the apartment. The notebook appeared to be a drug ledger, with names, weights, and amounts of money each person owed. The names included 31-year-old Steven Mark Chaney.

A few days later, an anonymous caller said that he and Mr. Chaney had bought cocaine at the Sweek apartment three to four times a week for months before the murders and that they went to the apartment a week before the murders. The caller ultimately identified himself as Curtis Hilton and said he worked with Mr. Chaney at a construction site. Mr. Hilton said Mr. Chaney owed John Sweek money at the time of the murders.

Police had found a partial latent thumbprint from Mr. Chaney’s left thumb on the wall of the Sweek apartment. Detective Westphalen and other officers then went to Mr. Chaney’s job site. Detective Westphalen later said that when he identified himself, Mr. Chaney immediately asked if the visit was about the murders. Detective Westphalen said it was, and Mr. Chaney told him he had eight witnesses who knew where he was on the night of the 20th and had not been in that apartment in three weeks.

Detective Westphalen arrested Mr. Chaney for two outstanding tickets and took him back to the police station. He interviewed Mr. Chaney and then released him.

On July 20, 1987, Detective Westphalen questioned Mr. Chaney again. During the interview, he noticed Mr. Chaney was wearing tennis shoes with soles that, in his opinion, resembled some of the bloody shoe prints in the apartment. Mr. Chaney agreed to take a polygraph examination. When police said he failed, Detective Westphalen confiscated the shoes and arrested Mr. Chaney on suspicion of capital murder.

During a pre-trial hearing, the defense discovered the prosecution had failed to disclose information favorable to Mr. Chaney, including evidence relating to Mr. Gonzalez as an alternative suspect. The judge reviewed the prosecution’s and Detective Westphalen’s files and ordered the evidence turned over.

The Trial

In November 1987, Mr. Chaney went to trial in Dallas County Criminal District Court, charged with both murders. Mr. Hilton was the prosecution’s first witness. A mistrial was declared when the defense discovered that the prosecution had failed to disclose a statement from Mr. Hilton.

In December 1987, a new trial began with Mr. Chaney charged only with the murder of Mr. Sweek. Mr. Hilton testified he and Mr. Chaney had purchased cocaine from Mr. Sweek as often as four times a week during the month prior to the murders, visiting Mr. Sweek’s apartment after work. Mr. Hilton told the jury Mr. Sweek often provided cocaine to Mr. Chaney on credit as long as Mr. Chaney paid a portion of his debt.

Mr. Hilton said the last time he and Mr. Chaney went to Mr. Sweek’s apartment together was June 13, 1987 — one week before the murders. Mr. Hilton said Mr. Chaney purchased one-fourth of an ounce of cocaine. At that time, Mr. Chaney did not have the cash to cover the $475 price, but Mr. Sweek provided the cocaine after Mr. Chaney paid some money on his existing debt. Mr. Hilton testified that when he went back to Mr. Sweek’s apartment the next day to buy more cocaine, Mr. Sweek said that Mr. Chaney’s debt of $500 was the largest of any customer and that Mr. Sweek “drastically” needed it paid in full.

Mr. Hilton said after the couple were killed, he talked to Mr. Chaney, who said he had cleared up his entire debt with Mr. Sweek. Mr. Hilton said after the police talked to Mr. Chaney, he came to Mr. Hilton’s apartment and said that Mr. Hilton was his alibi. He said that Mr. Chaney said “he needed to get out of town” since it was “too hot here.”

Investigator Vineyard testified that the partial latent thumbprint linked to Mr. Chaney was on a lower part of the kitchen wall, a location consistent with someone squatting or kneeling near the entrance to the kitchen. Investigator Vineyard said that in his opinion, the thumbprint had been left recently — an opinion that had no scientific basis.

Dallas County Sheriff’s Department Lieutenant James Cron testified that he compared Mr. Chaney’s tennis shoes to the prints in the apartment. He said Mr. Chaney’s shoes had a “pattern that is similar to the patterns” made on the kitchen floor. However, he said he could not say that Mr. Chaney’s shoes were the only shoes that could have made the prints.

Carolyn Van Winkle, a forensic serologist at the Institute of Forensic Science in Dallas, testified that she tested Mr. Chaney’s tennis shoes for traces of blood. She said no blood was visible, but that when she applied a chemical solution to the shoes, traces of blood were found in the right toe area and the upper left inner sole area. She said the traces were not sufficient to determine the blood type or even whether the blood was human or animal. She did say, however, that a presumptive test “came up fast” and, in her expert opinion, that was the normal reaction of human blood. She also testified that the tennis shoes appeared to have been covered with white shoe polish.

Dr. James Weiner, the medical examiner who conducted the autopsy on Mr. Sweek, initially reported that the bite mark was two or three days old at the time of Mr. Sweek’s murder. However, at trial, Dr. Weiner testified that the mark on Mr. Sweek’s lower left arm was inflicted “at or about the time of Mr. Sweek’s death.”

Dr. Jim Hales, chief dental consultant for the Dallas County Medical Examiner’s Office who was certified by the American Board of Forensic Odontology, testified that he examined Mr. Sweek’s arm the day after Mr. Sweek was murdered. He said both the upper and lower arches of Mr. Chaney’s mouth were consistent with and “matched” the bite mark on Mr. Sweek’s arm. He said that “only one in a million” people could have made the bite mark.

Dr. Homer Campbell, a private consultant in the fields of forensic dentistry and forensic odontology, testified “to a reasonable degree of dental certainty” that Mr. Chaney made the bite mark.

The defense presented the testimony of Dr. John McDowell, a board-certified forensic odontologist, who said that Mr. Chaney could have made the bite mark, but he could not state with any degree of certainty that he did. On cross-examination, McDowell conceded that Mr. Chaney could not be excluded from making the bite mark and that it was consistent with the models of Mr. Chaney’s teeth.

Charles Currier, an athletic footwear salesman, testified for the defense that the pattern on the bottom of Mr. Chaney’s shoes appeared on 50% to 80% of athletic shoes sold.

Several witnesses testified to Mr. Chaney’s whereabouts during the day and evening of June 20, the day the bodies were found. The construction site supervisor said that Mr. Chaney came to work at 7 a.m., but because of rain, work stopped at about 9 a.m.

John Hooper Sr. testified that Mr. Chaney was dating his daughter and living with them. Mr. Hooper said Mr. Chaney left for work at 5:15 a.m. and returned at 9:30 a.m. He remained there until 5 p.m., when he and other relatives went to Mabank, Texas, to pick up some furniture. On the drive, their truck had a flat tire and the repair was not completed until about 8 p.m. They then drove to another family member’s home and spent the night there.

The prosecutor argued to the jury that Mr. Chaney had killed John and Sally Sweek to avoid paying his drug debt. He relied heavily on the bite mark testimony, saying it was “better than eyewitness testimony.”

The defense argued that the evidence that Mr. Chaney made the bite mark was not conclusive and that Mr. Sweek likely had been murdered because he owed money to Mr. Gonzalez, his supplier.

On Dec. 14, 1987, the jury convicted Mr. Chaney. He was sentenced to life in prison. In 1989, the conviction was upheld on appeal.

The Exoneration

In 2015, Chris Fabricant and Dana Delger, attorneys for the Innocence Project, and Julie Doucet Lesser, a Dallas County assistant public defender, filed a petition for a writ of habeas corpus seeking to vacate Mr. Chaney’s conviction. The petition included a sworn affidavit from Dr. Hales recanting his “one in a million” testimony about the bite mark as “scientifically unsound.”

The petition also said that after the Dallas County District Attorney’s Conviction Integrity Unit (CIU) turned over the prosecution and police files in the case, Mr. Chaney’s lawyers discovered that Mr. Hilton had given several statements to Detective Westphalen. In the initial statements, which had not been disclosed, Mr. Hilton said that Mr. Chaney said Mr. Hilton was his “witness,” not his “alibi.” There were several other statements by Mr. Hilton that changed over time, including testimony at trial that cast Mr. Chaney in a negative light, the petition said.  Several of Mr. Hilton’s statements had been documented as untrue in the files, but that information was not disclosed.

The files also contained reports showing that Mr. Van Winkle was not the first analyst to examine Mr. Chaney’s tennis shoes and that the initial examination was negative for the presence of blood. A report from another analyst said the “spots are not blood.” Nonetheless, Detective Westphalen had testified before the grand jury that blood had been found.

The defense also discovered Dr. Hales initially said the odds someone else left the bite mark were “thousands to one” — later amended to say 100,000 to one, and at trial escalated to a “one in a million.”

Patricia Cummings, head of the Dallas County District Attorney’s Office CIU, supported the writ after conducting a lengthy re-investigation of the case and after extensive DNA testing of the evidence in the case excluded Mr. Chaney.

At least three male DNA profiles were discovered on or under Ms. Sweek’s fingernails, but not Mr. Chaney’s DNA. Mr. Chaney also was excluded as the source of hairs found in Ms. Sweek’s right hand.

Ms. Cummings reported that the prosecution had discovered a “vast amount of evidence” to support the original investigative theory that the Sweeks were murdered in connection with their drug dealings and debts to people with ties to the Mexican Mafia. 

On Oct. 12, 2015, Judge Dominique Collins ordered the conviction vacated and recommended that the writ be granted. Mr. Chaney was released after more than 25 years in prison.

In December 2018, the Texas Court of Criminal Appeals granted the writ, saying, “Mr. Chaney has proven that he is actually innocent.” The ruling noted that “each piece of the state’s trial evidence” had been rendered questionable, undermined, or completely invalidated.

On Jan. 16, 2019, Judge Dominique Collins dismissed the case. Mr. Chaney was subsequently awarded $2,260,000 in state compensation. In May 2021, Mr. Chaney died.