What constitutes a "substantial step" towards committing a crime?

And in cases involving planned offenses against individual victims, courts have focused on whether defendants had begun traveling to the location where the victim was expected to be found. See United States v. Washington, 653 F.3d 1251, 1266 (10th Cir. 2011) (holding that a defendant took a substantial step towards attempted murder-for-hire when he equipped himself with a pair of latex gloves to avoid fingerprints and traveled towards "a city in which he had no apparent business beyond the planned hit" with "the person who had facilitated the murder-for-hire agreement."); United States v. Young, 613 F.3d 735, 743 (8th Cir. 2010) (holding that defendant took substantial step towards enticement of a minor when he traveled to a motel where he expected to meet the victim); United States v. Khalil, 279 F.3d 358, 368-69 (6th Cir. 2002) (holding that a defendant took a substantial step toward committing a violent crime by participating with motorcycle club members who "organized themselves, armed themselves, and traveled in groups to locations where they expected to find their intended victims," and aborted their efforts only "due to police interference"); see also Model Penal Code 5.01(2)(a) ("lying in wait, searching for or following the contemplated victim of the crime" can constitute a substantial step).