The Case of the Unsent Text

When Marcus Havelock, a Hobart property developer, was found dead at the bottom of his office stairwell, police initially ruled it an accident — a simple fall, late at night, no witnesses.

Then someone noticed his phone. At 7:42 p.m., Marcus had typed a text message: “I know what you did. We need to talk.”

The message was never sent. Marcus died instantly from the fall. His phone was found in his hand at the base of the stairs, the unsent message still open on the screen.

Three people were in or near the building that evening. All three had reason to fear that message. Your task is to work out who killed Marcus.

The Suspects

Elisa Havelock – Business Partner

Elisa left the office at 7:35 p.m., telling security she had forgotten her laptop charger. She returned briefly at 7:50 p.m., found the stairwell blocked by emergency tape, and claimed she had no idea what had happened.

Noah Trent – Junior Project Manager

Noah says he was heading down the stairwell at 7:40 p.m. on his way to the car park and saw Marcus alive at the top of the stairs. He insists he left immediately and heard nothing unusual.

Karen Doyle – Neighbouring Tenant

Karen works late in the adjacent office. She claims she heard a loud argument coming from Marcus’s office at around 7:45 p.m., followed by a heavy thud.

The Physical Evidence

• Marcus’s phone was found in his hand at the bottom of the stairwell.
• The unsent text message was still open on the screen.
• His phone auto-locks after 30 seconds without contact.
• The phone remains unlocked if continuous pressure is detected on the screen.
• Marcus’s thumb was resting on the screen when he was found.
• Stairwell CCTV shows no one entering or leaving between 7:41 and 7:49 p.m. 
• Marcus died instantly from the fall.
  

Your Challenge

Which suspect killed Marcus Havelock? And is the key item of evidence that led to your conclusion?

The Solution

The unsent text

Marcus began typing the message at 7:42 p.m. His phone auto-locks after 30 seconds without contact, but remains unlocked if pressure is maintained on the screen.

When Marcus was found, the phone was:

• still unlocked
• still displaying the draft message
• with his thumb resting on the screen

This means Marcus was interrupted while typing, not minutes later.

Establish the moment of death

Because the phone stayed unlocked, Marcus must have fallen immediately after writing the message — while his thumb was still touching the screen. That places the moment of death very close to 7:42 p.m. Not 7:45 and not later.

The suspects

• Elise Havelock returned at 7:50 p.m. Marcus was already dead 
• Noah Trent claims to have seen Marcus alive at 7:40 p.m., which is consistent with the text being written two minutes later
• Karen Doyle claims to have heard an argument at 7:45 p.m., followed by a thud.

But Marcus could not have been alive at 7:45 p.m. If he had been, the phone would have auto-locked long before he fell.

Karen shifted the timing of the argument forward - not realising the unsent text fixed the time of death far more precisely than any witness could. She confronted Marcus immediately after he began typing the message, pushed him down the stairs, and later invented a safer sounding timeline.

Karen Doyle killed Marcus Havelock. The unsent text wasn’t a clue about motive.
It was a timestamp — and it told the truth when people didn’t.