NORRISTOWN — A 17-year-old Skippack boy accused of fatally stabbing his girlfriend after an argument in a park near the Perkiomen Trail wants to prevent a jury from hearing his alleged confession to police.
Tristan Brian Stahley, of the 4100 block of Rittenhouse Lane, through his lawyer Timothy J. Barton, filed papers in Montgomery County Court asking a judge to suppress from his trial the incriminating statements he allegedly gave to state police between May 25 and May 26, while he was questioned about the alleged killing. In those statements, Stahley, according to authorities, allegedly admitted to stabbing Julianne Siller on May 25 and directed police to the location of her body.
“Any statements made were involuntary in that they were the product of an overborne will and were the result of a weak, psychiatrically ill and deficient mentality, particularly susceptible to the suggestion, threats and coercion by police in the instant case,” Barton wrote in court papers.
Barton maintained any statements Stahley gave to police were the result of an illegal arrest without sufficient probable cause and “made contrary to proper legal procedures and without required constitutional safeguards.” Based on his age, experience, comprehension, and the absence of an interested adult when the statements were made, Stahley did not knowingly waive his constitutional right against self-incrimination or make a voluntary confession, Barton maintained.
Allowing a jury to hear the statements at trial would be prejudicial to Stahley, Barton implied.
A judge has not yet scheduled a hearing on the pretrial request. During that hearing, prosecutors will have an opportunity to challenge Stahley’s request.
Stahley, a former Perkiomen Valley High School student, is currently being held in the county jail without bail, awaiting trial on charges of first- and third-degree murder and possession of an instrument of crime in connection with the May 25 fatal stabbing of Siller, a 17-year-old from Royersford who was scheduled to graduate from Spring-Ford Area High School weeks later.
Authorities alleged Stahley, who was 16 at the time of the incident, stabbed Siller to death after an argument in a park near the Perkiomen Trail. Police and prosecutors charged Stahley as an adult but Barton has asked to have the case moved to juvenile court.
If Stahley is convicted of first-degree murder in adult court he could face life imprisonment. A conviction of third-degree murder in adult court could carry a possible maximum sentence of 20 to 40 years in prison.
If the case is transferred to juvenile court and the charges are proven, then Stahley could be kept under court supervision only until he’s 21.
Assistant District Attorney Jeremy Abidiwan-Lupo previously explained prosecutors cannot seek the death penalty against Stahley if he is convicted in adult court of first-degree murder, which is an intentional killing, in light of a 2005 U.S. Supreme Court ruling that deemed the death penalty unconstitutional for those who were under the age of 18 at the time of their crimes.
A life sentence also would not be automatic under a June 2012 U.S. Supreme Court ruling that deemed automatic life sentences for juveniles unconstitutional and required judges to consider factors such as juveniles’ life histories and their potential for rehabilitation in fashioning sentences.
Stahley and Siller had been dating “off and on” for about six to nine months at the time of the incident, according to court papers. The couple allegedly drove to the park off Creamery Road where they argued about Siller smashing Stahley’s phone and going out without him, according to court documents.
“Tristan said he used an orange handled EMT knife and stabbed Julianne in the throat and on her body,” according to the criminal complaint filed by county Detective Paul Bradbury and state police Trooper Barry Bertolet. “After the stabbing, Tristan said he then drug Julianne’s body into the woods to conceal her body.”
Authorities alleged the paramedic-style knife was found about 10 feet from Siller’s body.
After the alleged killing, Stahley returned home and threatened to kill himself with another knife shortly after confessing to his mother. Stahley’s father attempted to stop his son from committing suicide and struggled with the teen, suffering scratches to his face and a bite to his hand in the process, according to the arrest affidavit.
State police responded to the Stahley home about 10:21 p.m. for a report of a domestic disturbance and diffused the struggle between father and son. At that time, Stahley allegedly confessed to police and led troopers to Siller’s body.
An autopsy determined Siller died from multiple stab and cutting wounds.