A 29-year-old Colorado man is accused of deliberately crashing into his ex-girlfriend’s SUV, dragging her out of the vehicle, and fatally stabbing her on a rural roadway last month, according to a police affidavit.
Justin De Nileon Jr. allegedly tracked down 28-year-old Haley Rippetoe after she left her workplace on June 21 and intentionally struck her Nissan Rogue, causing it to veer off the road near the intersection of Weld County Road 7 and Weld County Road 6 in Erie, court documents state.
Investigators say the damage at the scene told a different story than a routine crash. The driver’s side window showed a punched-out, oblong hole, and the seatbelt had been sliced through with a sharp object — with several failed cut attempts visible above the final cut, according to the affidavit. Officers noted the blood found on and inside the vehicle, including on the seat, dashboard, and door panels, did not match what would be expected from a collision or ejection.
An autopsy later found multiple sharp-force wounds to Rippetoe’s torso, neck, and head, which the medical examiner determined were not caused by the crash itself but appeared to be inflicted deliberately by another person, the affidavit says.
Rippetoe’s body was discovered lying in a ditch beside the road after her brother and sister received automatic crash-detection alerts on their phones and rushed to the location. Their father, Ryan Rippetoe, told police he received the same kind of notification and immediately suspected his daughter’s ex-boyfriend was responsible, even before officers gave him any details, court records show.
Surveillance footage allegedly captured De Nileon fleeing the scene in a white SUV matching the vehicle involved in the crash. Around the same time, he reportedly placed a call to his parents in which he sounded distressed. His parents then contacted police in Broomfield requesting a welfare check — during which officers said they found him hiding under a tent, covered in blood that appeared disproportionate to the minor cuts and scrapes on his hands.
According to relatives, De Nileon had a history of abusive behavior toward Rippetoe, including previous incidents where he allegedly pushed her and tried to force her car off the road. He had also allegedly threatened her physically during past arguments, and was arrested in May on charges connected to an earlier kidnapping and assault involving her.
A protective order had been issued against him and was still active at the time of her death.
Ryan Rippetoe said his daughter had once told him a restraining order alone wouldn’t stop someone capable of kidnapping her in front of her young son. He said the moment he got the crash alert on his phone, he knew instinctively who was behind it, and later said the system meant to protect his daughter had failed her completely.
De Nileon was taken into custody last week and formally charged with first-degree murder. He is set to appear for a disposition hearing on September 2.