“You can’t do this to me,” Indianapolis Police Officer Francisco Olmos wrote an 18-year-old girl in a Snapchat message. “You can’t. I’m headed to your house right now.”

Hours later, the young woman would be dead, and her correspondences with Olmos deleted.

The young woman had been a member of the Indianapolis Metropolitan Police Department’s youth career program when her father found her dead of suicide on Nov. 2, 2015. But when detectives investigated the young woman’s case, they found one of their own officers suspiciously close to the death. Olmos, who had worked with the young woman through the youth program, had been outside her house even before she was found dead. While the girl’s father called 911, Olmos asked to used the girl’s phone to contact another officer.

And when investigators hired a company to crack into the girl’s phone this summer, they discovered that, in the moments after the girl was found dead, someone had deleted Olmos’ texts and Snapchats from the device.

On Thursday, police arrested Olmos on charges of obstruction of justice and computer trespass. Olmos, 31, claims he had a close, but non-intimate relationship with the young woman, and that he went to her house the day of her death because she left him a disturbing message.

But Olmos’ messages with the girl, recovered from her recently unlocked phone, suggest a more extensive communication.

Around noon the day of her death, the young woman called Olmos. He claims she called with compliments.

“She’s like ‘I want you to know that you’re a really good officer,’” Olmos told investigators shortly after the girl’s death, according to a probable cause affidavit in his arrest. “She said ‘you’re gonna make a fantastic SWAT officer.’”

Olmos knew the young woman through Indianapolis police department’s Explorer program, which trains teenagers for careers in law enforcement. The young woman joined the program when she was 16, and had done approximately 15 ride alongs with Olmos. The pair also worked out together and Snapchatted or texted frequently, according to the affidavit.

But when she called Olmos the day of her death, the young woman allegedly told him “I can’t talk to you anymore.” When he asked why, the young woman allegedly told him “it’s not your fault, nothing’s your fault.”

Then, just before hanging up, she allegedly told Olmos, “I love you, bye.”

Olmos told investigators she’d never told him she loved him before, and that her call made him uneasy. He said he tried calling back several times, with no answer. He said he went to the gym, but couldn’t shake the suspicion that something was wrong.

But records from the young woman’s phone indicate a more frantic mood. In the hours before the young woman’s death, Olmos tried calling her 16 times. He left 10 text messages and two Snapchat messages, according to the affidavit.

“Answer me you can’t do this to me AGAIN,” reads one of Olmos’ Snapchat messages shortly after the phone call. “I’m going to go to your house.”

The girl didn’t answer. “How can you ignore me like I’m just one of them,” Olmos messaged four minutes later. “You [can’t] do this to me. Please please.”

Two minutes later: “You can’t do this to me you can’t. I’m headed to your house right now.”

Ten minutes later: “You are gonna make me look so stupid in front of your family. I’m going to knock on your door.”

After several more unanswered messages and several hours, Olmos sent a final missive. “I don’t know what the point of ignoring me is,” he wrote. “You make me feel like this is really all my fault. I’m going to stop by your house at 439-5. I need to talk to you it’s urgent.”

Forty-five minutes later, the young woman’s father arrived at their home to find Olmos waiting outside. Olmos wanted to go in and speak with the young woman, but she wasn’t answering, he said. The girl’s father went into the house while Olmos waited in the garage. Then the father called for Olmos’ help. The girl was dead of a self-inflicted gunshot wound in her bedroom. Her iPhone was still on her bed, playing music.

The girl’s father picked up the phone to turn off the music. But while the phone was in the father’s hands, Olmos asked if he could use it to call another officer, according to the affidavit. The father gave Olmos the phone, and in those panicked moments, didn’t watch what Olmos did after placing the call, according to the affidavit.

But investigators from Olmos’ own department became concerned about what Olmos did with the phone. When detectives tried to access the young woman’s iPhone, they found it password protected, raising the question of how Olmos placed a call from the device. When an investigator asked the young woman’s parents for the passcode, both insisted that the device had not been password protected.

The girl’s brother insisted that “their phones were always lying around, and you could pick either one up and make a call. Their phones did not have passcodes on them,” according to the affidavit.

Police sent the device to Cellebrite, a firm notorious for helping law enforcement hack into locked cellphones. Cellebrite’s first efforts to unlock the phone failed. But by summer 2017, the company had unveiled a new program that allowed officers to unlock the woman’s phone and run it through a forensic investigation.

They found what looked like a sloppy coverup. Olmos and the young woman had texted 177 times between Oct. 31 and Nov. 2, when she died. Those messages were deleted from the young woman’s phone after she was found dead, but before first responders arrived at the house—when it was just Olmos and the girl’s father in her room, with Olmos holding the phone. But police could still access SMS records indicating when the messages had been sent, and when they had been deleted.

And investigators found the biggest clues in the young woman’s Snapchat history. Snapchat allows users to send messages that appear to vanish after they are viewed. Despite the app’s apparent emphasis on privacy, it still hoards some messages in the background.

“While they appear to be deleted to the user of the phone, these text messages can sometimes be recovered using forensic software,” the affidavit reads. “There were 9 videos and 1 photo that had been sent via snapchat to Francisco Olmos that were recovered.”

One minute after the young woman’s texts with Olmos were deleted, someone opened her Snapchats from him, appearing to make them disappear.

Little did that person know, the messages would linger on the device for two years, revealing Olmos’ last pleas as he drove to the young woman’s house.

“You can’t do this to me,” he messaged over and over, “you can’t.”