Thinking of planning on a new plot line - - Ava shows up at her sister Sara's door trying to escape her abusive husband Greg. Sara shelters Ava in her house for 24 hours and then reports her as a missing person. Together the sisters fake a photo of Ava dead and send it anonymously to the police. The police start investigating Greg. In the meantime the sisters start gaslighting Greg (making sure he catches glimpses of Ava everywhere etc.) in an effort to drive him crazy. Is this plausible?
The main problem I see is once a missing person's report is filed, the police are going to start looking strongly into everyone close to the missing person. The chances that Ava and Sara are caught and charged with filing a false report is quite high. If caught it wouldn't be long before the police would probably pin the fake photo on them as well and they would be in a world of what the French call "merde". As for driving him crazy, more than likely, it would drive him very angry and dangerous (I mean he already has an abusive tendency). Since he knows that Ava is not dead and he is being investigated by police about her disappearance and possible death so by seeing her he probably has a pretty good idea he is being set up. Depending on how dangerous he gets he might get a gun and start shooting at those attempts at gaslighting.
Another thing to consider, the police rarely get evidence just mailed to them in murder cases. If they do, it's usually some serial killer taunting them, or perhaps a tip from someone that may have an idea on who the killer is. But a photo? I don't know if that fits a murder as the result of domestic abuse. Spoiler In the movie 'Winter's Bone' there is a missing persons case involving a guy that jumped bail (actually he was murdered cause he was going to snitch), and a group of women who know the location of the dead body offer to help the daughter so she can keep her house (offered for collateral for the bail bond). They cut off one of the corpse's hands, and the daughter says "are we done?" and they say "No, we have to cut both. If we cut one they'll think he is alive and cut one off to avoid prison." They tell her to take both hands to the police and tell them someone threw them on her porch. I don't know if that's how the police would really react to a single hand versus two, but it seemed logical. To me, the photo would have to be very clear to cause them to conclude she's been murdered without additional evidence. In 'Gone Girl' (the movie) the police did conclude she was dead without a body, but they had blood, signs of a struggle, a motive, and later, a murder weapon.
Ultimately the end result would be the sisters getting charged with a number of quite serious offences. If the Police treated the initial missing person report as genuine they would dedicate a decent amount of resources to locate her, including phone tracking. I don't think it would stand up to scrutiny, especially if the husband is seeing his wife and the police would probably put two and two together quite quickly when they receive the staged photo.
The fact that there's no body puts a serious strain on any kind of real case. It would only be an alleged murder with no proof that it actually happened.
If you really want to deceive the husband, you could possibly go with asocial media type of retribution. -Ava leaves her husband, goes to stay with Sara. (Names are too similar for me, BTW.) -They leave Ava's car in a large parking lot (mall, box store, etc.) and go back to Sara's house, where Ava stays completely incommunicado. -Sara starts to continuously call abusive husband wanting to speak to Ava. "Where is she!?!?!?!?!? What have you done to her?!?!?!?" -Sara and Ava use greenscreen and stock backgrounds to create pictures for her social media accounts. -The pictures show she is in Philidelphia one day, Boston a few days later, Tulsa a week after that. The idea is to get abusive husband to chase her supposed social media trail all over the country as the sister's plan Ava's escape from abusive husband. ----- Variation on the theme = They go on the run to Portland but post pictures from Miami. (Probably more fun and more tension as the abusive husband figures things out and starts to chase them.) Hey, just my two ducats.
Re: no body. This was a case with no body from Wyoming in 2007. https://charleyproject.org/case/lynn-lynette-bush Might give you some ideas to set your character up for a murder charge.
TY for all the feedback. Forgot to add, the sisters dump Ava's cellphone in the woods (thought about adding something with Greg's DNA too but seemed like too obvious a setup). Also -since everyone assumes Ava is dead Greg only THINKS he saw her but he can't be sure.
Since there is a photo but not a body, how the police responds to the fake photo might raise questions and curiosity in the readers.
If I was going to make this plausible I'd skip the photo. 1. Have Ava call Police from her sister's house. 2. Have Police attend and record a statement alleging domestic violence. 3. Before the Police leave, have Ava tell them she intends to return home. 4. Have Ava leave her car and things at home and then put in the disappearance plan. 5. Sister makes the missing person report.