Generally speaking, Bogotá's south is a bit more dangerous, while the north is, on the whole, a different story. Many locals walk well after dark between, say, Zona Rosa and Parque 93's club and restaurant scene, whereas in La Candelaria you'd want to be way more cautious.
Since the mid-'90s Bogotá has made many significant advances, among them reducing its homicide rate from 80 murders per 100,000 residents in 1993 to 15.8 in 2016 (mobile-phone theft fell by 20% from the previous year as well). These statistics mirror the downward trend of the overall Colombian murder rate for the same year (it was the lowest in four decades). Today Bogotá is one of the safest urban areas in Latin America – so safe, in fact, that Pope Francis visited in 2017.
In 2016 the Colombian government and the Fuerzas Armadas Revolucionarias de Colombia (FARC; Revolutionary Armed Forces of Colombia) signed a historic cease-fire deal, so Bogotá potentially sees fewer bombings than it did at the height of Colombia's armed conflict, but that doesn't mean the bombings have stopped entirely: an explosion at Centro Comerical Andino killed three people in 2017. (The bomb was attributed to members of a smaller urban guerrilla group known as the Movimiento Revolucionario del Pueblo, or MRP; this was its first attack to cause fatalities). Also in 2017, a bomb injured 29 (26 were police officers) in La Macarena. Though no arrests have been made, known members of the National Liberation Army (ELN) are wanted for the attack. While tourists are not specifically targeted, it's easy to be in areas where these things happen. Thankfully, the Colombian government announced a cease-fire with ELN in late 2017, and wavering peace talks in Havana, Cuba, continued through 2018; Bogotà – and Colombia – breathed a sigh of relief.
Hostel owners report a considerable drop in robberies in La Candelaria, which is generally safe during the day but can still be dicey at night. Always be aware of your surroundings. Be wary of handling your phone near the edge of streets, as thieves on motorcycles and bikes have been known to ride by and snatch them. If you opt to stay in La Candelaria, choose accommodations based not only on your general criteria but also on security. Avoid walking alone or with anything valuable after dark – these days the area has more of a police presence at night, though it's still a far cry from the show of force during the day.
Muggings are common around Calle 9 up the hill nearer the poorer neighborhood of Barrio Egipto, which remains a notable hot spot. Although tours of the barrio are now offered, under no circumstances should you wander there on your own. Do not stray beyond Carrera 1. At the Barrio Egipto's northern end there's private security in Parque de los Periodistas (you'll see personnel walking around with dogs) hired by the universities, so this once-sketchy area is now a lot safer. Solo travelers should always exercise caution on the road between the Universidad de Los Andes and Monserrate, though a police presence on the mountainside trails from 6am has curbed incidents here dramatically.
Police presence has been stepped up in La Macarena as well, though it's still a good idea to take a taxi and stick to the main restaurant streets – La Perseverancia barrio, just north of La Macarena, has a very dodgy reputation and it's not difficult to stray into it if you're unfamiliar with the area.