David Madsen

"Since only I know what's happening."

- David to Max in "Dark Room. David N. Madsen is a supporting character in the 2015 episodic point-and-click game, Life is Strange. David is a former military soldier working at Blackwell Academy as the head security guard, and also Chloe Price's stepfather. He is an anti-villain, later becomes a anti-hero/supporting protagonist, depending on the player's choices.

Chrysalis
David is first seen confronting Max Caulfield, the protagonist of the game, after she saves Chloe from being killed by Nathan Prescott. He is later seen bullying student Kate Marsh, at this point, the player can decide to help Kate or take a photo of the incident. In the Price house, Max discovers David's security system within the house and his plan to install multiple cameras in the academy, Max also discovers photos of students, including Kate Marsh. During her time in Chloe's room, she may hide in her closet and sees David having an argument with Chloe, the player decide to stay in the closet or intervene.

Out of Time
He is first seen confronting Nathan Prescott for unknown reasons. It was revealed by a homeless woman that David is a hated man among other residents of Arcadia Bay. After Kate Marsh's suicide or attempted suicide, the player can decide to blame David for the incident.

Chaos Theory
At the beginning of the episode, if David was placed on temporary leave earlier, Max will find a website set up by an unknown number of Blackwell students attempting an online petition to have David dismissed from his job as Blackwell head of security in her laptop. Otherwise, no website with any mention on David Madsen will be found.

When Chloe and Max are entering the school building with David's spare keys at night and searching for clues regarding Rachel Amber's disappearance, Max finds an email from David to Michelle Grant regarding her petition against his surveillance system plans, in which David states, despite being nobody's favorite among the students and faculty, making sure their safety is his prime directive. He refers to the 15.4% drop in campus crime since him taking over as Head of Security and asks her to redact her petition and to reconsider the negative consequences. Memos from Wells' computer reveal that he had accused Rachel Amber of drug dealing prior to her disappearance, and furthermore that he has been following her and taking pictures.

After that, Max and Chloe head to the Blackwell swimming pool where they are disturbed by security staff members.

If David is not placed on temporary leave, David will be supervising the security sweep through the Blackwell swimming pool area and he will have to write vandalism reports all night.

If David is placed on temporary leave, another unnamed security guard will take over as Blackwell head of security in David's place and will supervise the security sweep through the Blackwell swimming pool area instead.

Support Chole
While Max is descending the stairs, David is seen looking at the family photos. Max later comments that his reaction to the photos isn't any different from hers. After having a conversation with Max, David leaves the household, feeling cross that Max managed to break up the family. He gives a small warning about wandering around Chloe. Joyce leaves him a note telling not to be home when she returns from work. It also becomes apparent that David made a reservation at the Bloch Hotel. Max can find an unfinished crumpled letter to Joyce lying on the garage table. The car is no longer present, implying the fact that the repairs have been finished.

Support David
David can be found working at his workshop after finishing his car repairs. Max can talk to David about whatever he knows as a follow-up to the case revolving Kate, with David noting that Max has done more to help Kate than anybody else, and feeling bad that he has left the roof open for Kate's (attempted) suicide. David also reveals the reason behind the need for the additional surveillance in the school but remarks to Max that she herself is a walking surveillance. If Nathan hasn't been suspended, David comments on him as a "little shitass" who should be lucky that he didn't get suspended, and apologizes for not having had all the evidence at the time. Furthermore, he states that he's the only one knowing what's happening and that he wanted to protect future students from ending up like Rachel Amber and Kate Marsh. Since he is off duty, he is free to criticize Mr. Jefferson as an "elitist prick". He ends the conversation by warning Max this is dangerous territory she is heading into since she already knows way too much of what is happening at Blackwell.

We can also find out that David has treated Joyce to the most expensive restaurant in Arcadia Bay for over 260$ after their confrontation on the last evening.

Polarized
After changing the past twice and finding herself again in the Dark Room, no matter who Max supported, David used the clues found by Chloe and Max's investigation and successfully tracked to the source behind the attacks on students and found himself in the Dark Room, fighting with Mark Jefferson. With the guidance and a bit of manipulation of the playing field by Max, David successfully knocks out Mark Jefferson and frees Max. David reconciles with Max (regardless of which options were picked in the conversation) and tells her he also suspected Nathan in his role behind Kate's (attempted) suicide and should have apprehended them sooner. He also admits that he was being too harsh on Kate.

However, if Max is to reveal to David of Chloe's death, David will shoot Mark in the head for revenge. Otherwise, he will be continuing the investigations at the desk in the Dark Room.

When the timeline has been rewinded through Warren Graham's photo to prevent Chloe's death at the hands of Jefferson, Chloe and Max reported their investigations to David. David promptly tracked Mr. Jefferson to the Dark Room and had him arrested with the help of the police.

Sacrifice Arcadia Bay
It's unknown what's happened to him in the Sacrifice Arcadia Bay ending, but it's presumable that he died during the storm unless he stayed inside the bunker.

Sacrifice Chole
If the timeline is reversed and Chloe had been shot dead by Nathan back in Blackwell, David is the first who enters the bathroom and arrests Nathan. David will be among the attendees at her funeral together with his wife Joyce, clearly being in mourning about Chloe's death. Kate as one of the attendees will stop at them and comfort them.

Trivia

 * David is considered the least evil antagonist.