Chapter 3 of "The Trials of Marvin Mutch" podcast series covers the prosecution and conviction of Marvin Mutch for the murder of 13-year-old Cassie Riley. Prosecutors were able to obtain a conviction based on a complex chain of circumstantial evidence, which Mutch would later appeal as insufficient to merit a first-degree murder conviction.
The prosecution's key witness against Mutch was his then 16-year-old sister, Valerie, who was housed with a district attorney's investigator for months leading up to the trial and her testimony. It's unclear who involved in Mutch's trial was aware of Valerie's living situation, and when. But the jury never heard about it.
Explore case notes, selected trial transcripts, news reports and photos related to the trial below.
Union City detectives interrogated Mutch for hours the night of his arrest, starting at 1:50 a.m., according to the record of the statement he gave to police.
The following synopsis gives more details about Mutch's initial, and only, interview with police. The synopsis of the interview appears to be written from an audio recording of the questioning, which is referenced several times at hearings leading up to Mutch's trial. Neither the audio tapes themselves nor a complete transcript of the interview were provided as part of the Union City Police Department's record of the case.
Sister is Star Witness
Valerie Mutch attempted suicide a few days after her brother's arrest.
Valerie Mutch said a week or two later, she started living with district attorney's investigator Phil Fry.
Marvin Mutch's defense attorney was looking for Valerie for months leading up to the trial, but he was unable to determine where she was living. That and other issues with the defense's access to evidence are argued in the incomplete pretrial transcripts below.
Valerie Mutch testified on May 9, 1975.
Read the transcript of her testimony below.
Mutch's defense attorney James McWilliams argued that shoe prints near Cassie Riley's body showed someone else had killed her.
Read the full arguments of the attorneys below.
The jury found Marvin Mutch guilty of first-degree murder for killing Cassie Riley. He later received a 7-to-life sentence.