Inside the haunting Trailside Killer case

[0:04] This is the area and probably the trail that my sister was hiking on. [0:11] Over the hill there, you could see San Francisco Golden Gate Bridge. [0:17] And she would have come up here to come look at the sunset late in the afternoon. [0:24] The next morning, my mother called and told me that Annie's missing. [0:27] This is the story of a serial killer who hunted his prey, human beings, specifically women, in the most beautiful places you can imagine. [0:39] You never know what or who is hiding just off trail. [0:47] To this day, people are still haunted by the trailside killer. [0:51] The damage and the trauma done to the victims, the survivors, and their families is immeasurable. [0:58] It lives on. [0:59] My mom survived a serial killer and literally lived to tell the tale. [1:05] The trailside killer was baffling the authorities and terrorizing the public. [1:09] It was a very traumatizing time for people in Northern California. [1:12] He didn't feel safe anywhere now. [1:15] He had this insatiable appetite to hurt women. [1:22] Murder after murder. [1:23] For years, the serial killer gripped the region in fear. [1:27] The shockwaves hadn't even settled when the Bay Area was rocked by the trailside killer again. [1:32] His objective was to rape and murder and get away with it. [1:36] To him, that was the ultimate crime. [1:39] We have, on our hands, a killer with severe psychological problems. [1:45] Tonight, inside the case, the hunt for clues and the search for answers. [1:49] The natural landscape of Marin County is rolling hills that roll down into the Pacific Ocean. [1:59] One of the dominant features in the area is Mount Temelpais. [2:03] And Northern California has the best of everything here. [2:07] There's very little crime. [2:08] So it was very safe. [2:09] And when these killings started happening on the trails, killings of women, rapes and murders, it shattered everything. [2:19] Nobody felt safe anymore. [2:21] The scientist and daughter of a prominent Marin doctor was found shot to death by a high-powered weapon. [2:26] On October 13th, Ann Alderson met her death ambushed on a trail. [2:30] My sister was Ann Evelyn Alderson. [2:36] She was the victim in the trailside murder saga. [2:43] She was 26. [2:45] I would say she was beginning the prime of her life. [2:49] She had a lot of freedom to say, gee, the world is my oyster. [2:53] I'm really excited about what comes next. [2:56] She really, really loved being outside in the forest. [3:03] She worked as a forest ranger. [3:04] This was something that was so far beyond our imaginations at the time. [3:10] My sister went off abroad and was working with the Peace Corps. [3:16] And so when she came back, she was not updated on that there had been a couple murders in the area. [3:23] Annie had no idea of the trailside killings. [3:26] I think what my sister found in nature is she found peace. [3:30] She found a place where she could meditate. [3:33] The night she died, by the reports of hikers and so forth in the area, she was spotted up in the Mount Tamalpais Mountain Theater. [3:54] She was just kind of up there watching the sunset and enjoying the evening. [3:59] I heard about it the next morning when my mother called and told me that Annie's missing. [4:05] We knew something was wrong. [4:10] Alderson's killing was found to be committed with a .38 caliber weapon. [4:14] What was most frustrating about not knowing who murdered my sister, I think, was the fact that the worry that other people were going to fall victim to him. [4:26] So when it did happen again and again, you're just, your heart broke. [4:31] The trailside killer was suspected of at least seven killings before he was finally unmasked. [4:36] Shortly after 7 a.m., the silence this neighborhood is accustomed to was broken when Department of Justice agents, the FBI, and members of the Marin County Task Force converged in a home at 38 Sussex, [4:50] arresting 51-year-old David Joseph Carpenter as the suspected trailside killer. [4:55] David Carpenter would be convicted of those seven murders. [4:58] But one of his first would-be victims, the mother of actress and Real Housewives star Lisa Rinna, more than two decades earlier. [5:06] He's working, and one of his colleagues, Lois D'Andrade, is someone that he has his eye on. [5:12] I think my mom was positive and never played a victim, never felt sorry for herself, and she could have been the most miserable, [5:24] f***ed up, traumatized human being, and I never saw that. [5:29] I've seen clips of Lisa Rinna talking about her mother on The Housewives of Beverly Hills before. [5:34] He's straddling me, and he had a hammer in one hand, a knife in another. [5:40] I was the first one that he went to jail for. [5:43] And so one morning she was waiting at the bus stop to go to the dentist, and he came by the bus stop and said, [5:49] Lois, I want you to meet my new baby. [5:52] She was like, no, I have to go to the dentist. [5:54] And he's like, I'll drive you. [5:55] And she got in the car with him. [5:57] He started talking to her, and he was not stuttering. [6:00] That was the first sign. [6:04] He was driving in a weird direction, and then she said, David, what's going on with you? [6:10] You're not stuttering. [6:12] You're speaking clearly. [6:14] And he said, I don't know, Lois. [6:16] Something just comes over me. [6:18] And that's when she knew she was a f***ed. [6:22] But then he starts driving, instead of towards their house, through the Presidio, [6:27] which is an army base here right at the foot of the Golden Gate Bridge. [6:29] Now, it's maybe 10 in the morning. [6:33] Luckily, a military policeman saw this car drive down a deserted road that no one should be driving on. [6:40] So he followed them. [6:42] And as David Carpenter parked the car, he literally straddled my mom, grabbed a knife out of the glove box, [6:51] takes the knife, goes at my mom. [6:53] My mom grabs it with her hand, and it severs these two fingers. [6:57] So her fingers are, like, dangling. [6:58] And then David starts to freak out because he sees the car coming. [7:04] And so he reaches in the back, grabs a hammer, and starts smashing my mom over the head with a hammer. [7:08] He starts hammering at her head. [7:11] If that police officer had not shown up when he did, Lois would be dead. [7:16] The MP shoots David Carpenter in the stomach. [7:21] Doesn't kill him. [7:22] My mom, she's in the hospital for three months. [7:26] She had to have a big metal plate put in her head. [7:28] David Carpenter then pleads guilty. [7:32] Then he goes on to become the trailside killer. [7:36] David Carpenter received 14 years in federal prison for the attack on Lois DeAndrade. [7:42] He ended up serving nine. [7:44] Authorities have linked the trailside killer to other cases. [7:48] Most investigators believe that there are still victims of David Carpenter that haven't been identified or endlessly tied to him. [7:56] There are several. [7:57] Which makes you think, could there be other victims out there? [8:02] Right now we're headed up to a set of picnic benches that are by the parking lot. [8:12] I've been told, I've not seen it, but there's a plaque in memory of all the women that were victims of the trailside killer. [8:19] The plaque here reads, forever on the mountain. [8:25] And then it names the three women that died in this area. [8:31] And Alderson, age 26, from Terralinda. [8:35] Love is never ending. [8:37] I think that's a really nice thing. [8:42] I'm very proud. [8:44] Proud that people would remember her. [8:48] It's a lovely setting. [8:52] And people always will remember and enjoy this spot. [8:56] And for much more on this story, including additional details from Lisa Rinna about her mother's attack, watch Terror on the Trails, now streaming on Disney Plus and Who.